A Revision of the Chilodontidae (Gastropoda: Vetigastropoda: Seguenzioidea) of Southern Africa and the South-Western Indian Ocean

ABSTRACT All species of Chilodontidae known to occur in the south-western Indian Ocean are discussed (27 species, of which eight new, belonging to nine genera, of which three new). Keys to genera and species are provided. Observations on protoconch form, shell microsculpture, radula morphology, operculum shape and external anatomy are given, together with summary biological observations. The genus Agathodonta Cossmann, 1918 is not considered to be applicable to the extant species for which it has been recently used and a new genus is proposed for these living forms. Type specimens of a number of extralimital species examined for comparative purposes are illustrated. New genera: Ascetostoma, Clypeostoma and Pholidotrope. New species: Clypeostoma reticulatum, Danilia boucheti, Danilia textilis, Herpetopoma serratocinctum, Herpetopoma stictum, Pholidotrope gloriosa, Vaceuchelus cretaceus and Vaceuchelus jayorum. New synonyms: Cantharidus pliciferus Schepman, 1908 = Perrinia angulifera (A. Adams, 1853); Turcica (Perrinia) waiwailevensis Ladd, 1982 and Herpetopoma eboreum Vilvens & Héros, 2003 = Herpetopoma xeniolum (Melvill, 1918); Trochus alabastrum Reeve, 1858 = Euchelus asper (Gmelin, 1791). New combinations: Agathodonta elongata Vilvens, 2001, A. meteorae Neubert, 1998, A. nortoni McLean, 1984, Euchelus townsendianus Melvill & Standen, 1903 and Turcica salpinx Barnard, 1964 are transferred to Clypeostoma gen. n.; Diloma verruca Gould, 1861, Euchelus seychellarum G. & H. Nevill, 1869, Euchelus xeniolum Melvill, 1918, Turcica helix Barnard, 1964 and T. waiwailevensis Ladd, 1982 are transferred to Herpetopoma; Euchelus gemmula Turton, 1932 is transferred to Vaceuchelus; Euchelus providentiae Melvill, 1909 and E. ringens Schepman, 1908 are transferred to Ascetostoma gen. n.; Stomatella cumingii A. Adams, 1854 is transferred to Granata; Turcica konos Barnard, 1964 is transferred to Perrinia. New records for the south-western Indian Ocean: Clypeostoma meteorae (Neubert, 1998); Clypeostoma cf. nortoni (McLean, 1984); Granata cumingii (A. Adams, 1854); Herpetopoma instrictum (Gould, 1849); Herpetopoma ?naokoae Poppe, Tagaro & Dekker, 2006; Herpetopoma xeniolum (Melvill, 1918); Perrinia angulifera (A. Adams, 1853). New records for South Africa: Ascetostoma providentiae (Melvill, 1909); Herpetopoma ?naokoae Poppe, Tagaro & Dekker, 2006; Perrinia angulifera (A. Adams, 1853). Lectotypes designated for: Euchelus favosus Melvill & Standen, 1896; Euchelus gemmula Turton, 1932; Euchelus natalensis Smith, 1906; Euchelus seychellarum G. & H. Nevill, 1869; Euchelus townsendianus Melvill & Standen, 1903; Monodonta alveolata A. Adams, 1853; Monodonta angulifera A. Adams, 1853; Stomatella articulata A. Adams, 1850; Turbo semilugubris Deshayes, 1863. Type locality designations and emendations: Type locality for Stomatella cumingii Adams, 1854, designated to be tropical East Africa; type locality for Turcica salpinx Barnard, 1964, selected to be ‘off Cape Morgan, 77 fath.’ [-141 m]; type locality of Turcica stellata A. Adams, 1864, emended from ‘China Seas’ to Gulf of Suez, Red Sea. Danilia Brusina, 1865 is deemed a nomen protectum and Heliciella O.G. Costa, 1861 a nomen oblitum.


INTRODUCTION
The taxa discussed in this revision have traditionally been referred to the trochid sub families Margaritinae and Monodontinae (see for example Keen 1960). McLean (1981McLean ( , 1982, however, identified certain lineages within these subfamilies that shared dis tinctive features of the shell, radula and epipodium. He proposed (McLean 1981) that these represented Recent descendents of Mesozoic lineages (Amberleyidae) previously thought to have become extinct in the Oligocene or earlier. He later suggested (McLean 1982(McLean , 1984) that they be recognised as separate tribes within the Margaritinae, but this idea was subsequently revised in the publication of Hickman and McLean (1990) in which a much modified trochoidean subfamily, the Eucyclinae, was employed for the taxa concerned, based on the extinct families Eucyclidae, Cirridae and Amberleyidae. This subfamily was further divided into three tribes, the Eucyclini, Calliotropini and Chilodontini (the latter two including extant taxa) on the grounds of differing shell morphology, radula form and external anatomy. Warén and Bouchet (1993), on account of uncertainties regarding the affinities of the exclusively fossil Eucyclini, subsequently chose to regard the other two tribes as subfamilies in their own right, although this was not followed by Hickman (1998).
A radically different position was subsequently proposed by  in which the Calliotropinae and Chilodontinae were removed from the Trochoidea and referred instead to the Seguenzioidea, largely on the basis of molecular data (Warén et al. 2003). More recently, Kano (2008) has analysed the relationships of the Seguenzioidea using sequence data from a wider range of taxa and has confirmed that calliotropine and chilodontine species cluster together with seguenziids in a well supported clade, although no support was evident for the monophyly of either the Calliotropinae or Chilodontinae, nor for the two treated together as the Chilodontidae. He also highlighted potentially significant anatomical similarities including a peduncle posterior to the right eyestalk (distinct from the subocular tentacle) and hooded rachidian teeth in the radula, but poin ted out that these may be plesiomorphic character states. Subsequently, Williams et al. (2008) recovered a monophyletic Chilodontidae, with monophyletic subfamilies Chi lodontinae and Calliotropinae, but their study did not include other seguenzioid taxa. Most recently Kano et al. (2009), including additional seguenzioid taxa, recovered well supported Chilodontinae and Calliotropinae clades, but found no support for the combined Chilodontinae + Calliotropinae clade. Consequently, they proposed that the two groups be recognised as separate families within the Seguenzioidea. Further support for the seguenzioid affinities of these families was recently provided by Aktipis and Gi ribet (2012). Kano et al. (2009) also demonstrated that Turcica H. & A. Adams, 1854, tra ditionally grouped with chilodontid taxa (Hickman & McLean 1990), belongs within the Calliotropidae. For the purposes of this revision, I follow the recommendations of Kano et al. (2009); however, it should be noted that Bandel (2010) has proposed a very different classification for the taxa discussed here, in which he recognised a superfamily Eucycloidea and proposed several new families.
Since chilodontids have only recently been recognised as a distinct entity, there has been no previous collective analysis of the group in this region. In many cases little in formation over and above that contained in the original descriptions is available. Hick man and McLean (1990) considered the genus Synaptocochlea Pilsbry, 1890 to be long to this group, but although it occurs in the south-western Indian Ocean, it is not treated here. Morphological and molecular evidence now indicates that Synaptocochlea belongs within the Trochidae (Herbert 1998;Williams et al. 2008Williams et al. , 2010, in the subfamily Fossarininae Bandel, 2009. Another western Indian Ocean genus which Bandel (2010) referred to the Eucycloidea is Pagodatrochus Herbert, 1989, creating for it a new family, the Pagodatrochidae. Whilst this taxon shares some features of early teleoconch ribbing and microsculpture with chilodontids and has a radula somewhat atypical of trochids, the proposal of a new family in the absence of corroborating evidence from soft-part anatomy and molecular data seems premature. In terms of its external morphology there are no cephalic lappets or laterally expanded snout flanges, nor is a right post-ocular peduncle evident, and the ctenidium is monopectinate (Herbert unpubl. observ. on the type species Pagodatrochus variabilis (H. Adams, 1873)). None of these character states suggests a closer relationship with the Chilodontidae than with the Trochidae. It is evidently one of many small, anomalous vetigastropod taxa for which molecular sequence data could provide valuable phylogenetic insights.

MATERIAL AND METHODS
The material studied is kept in the following institutions: The bulk of the material discussed in this work was obtained during the Natal Museum Dredging Programme (1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997) off the east coast of South Africa, on board the RV Meiring Naude and RV Sardinops. This has been augmented by additional material from Madagascar, Mozambique and Réunion obtained during the BENTHEDI (1977), MAINBAZA (2009), Miriky (2009 and ATIMO VATAE (2010) campaigns (MNHN) (see acknowledgements). Littoral and shallow water material has also been accumulated over many years and from throughout the region, during the course of on-going field research and through the collecting activities of amateur malacologists.
Shell length and diameter measurements were made with the shell held in apertural view with the axis of coiling vertical. Immature shells were excluded from the data used to calculate length:diameter ratios. The dimensions of the protoconch were measured according to the method set out previously (Herbert 1987). Photographs of shells were taken with a Nikon F4 or Nikon D70 camera. Radulae were extracted by maceration of the buccal mass in dilute NaOH and then thoroughly rinsed in distilled water. For light microscopy radulae were stained in Shirlastain A [SDL Atlas] and for SEM they were dehydrated in ethanol, placed on stubs with double-sided carbon tape and manipula ted into position using fine entomological pins whilst air-drying. Shells and radulae for SEM examination were coated with gold-palladium and examined at low accelerating voltage (5-10 kv) in Jeol T/200, Hitachi S-570 SEM, Philips XL30 ESEM and Zeiss EVO 10LS scanning electron microscopes.
The following acronyms and abbreviations are used in this paper: CSIR -Council for Scientific and Industrial Research, South Africa; Coll'n -Collection; Exped'n -Expedition; IIOE -International Indian Ocean Expedition; KZN -KwaZulu-Natal; L/D -length:diameter ratio; L(S)T -low (spring) tide; NMDP -Natal Museum Dredging Programme; NPB -Natal Parks Board [now Ezemvelo KZN Wildlife]; s.d.
In some species the terminal lip is straight or very slightly curved, but a number have developed a strong beak or sinusigera-like projection (Fig. 1B,C). This is only visible in the most well preserved protoconchs, but the strong angulation in the somewhat worn protoconchs of a number of other taxa is perhaps evidence of the occurrence of a similar structure (e.g. Ascetostoma providentiae, Perrinia angulifera and Vaceuchelus cretaceus). I am not aware of any prior reports of such a projection on the protoconch lip in the Vetigastropoda, although some seguenziids have a protoconch with a strongly convex lip (Marshall 1991). A beak or sinusigera-lip is found in the pelagic larvae of a wide variety of caenogastropods and is thought to be indicative of relatively long-lived, planktotrophic larvae (Lima & Lutz 1990;Fretter & Graham 1994). Its presence in lecithotrophic vetigastropods is less easy to explain, but could perhaps indicate a larger velum and a longer, more active swimming phase than is typical for vetigastropods. None of the species examined show any kind of varix (terminal or subterminal) associated with the protoconch lip.
The different patterns evident in the superficial sculpture of the chilodontid protoconch can be grouped as follows: almost totally smooth, usually exsert and rather globose [ -Perrinia konos, Pholidotrope gloriosa] (Fig. 1A).
Vaceuchelus), in others less so (e.g. Perrinia). For the majority of genera, however, data on protoconch microsculpture are available for too few species to assess its intrageneric consistency. Similarly, there is also variation in the size of the protoconch and its elevation above the first teleoconch whorl. In most species protoconch diameter lies between 200-300 μm; however, in Clypeostoma salpinx, Danilia textilis and Vaceuchelus gemmula, proto conch diameter may reach 340-380 μm. This appears to be more of a species character than a generic one, as other species in these genera have protoconchs within the 200-300 μm range. Mostly the protoconch projects a little above the first teleoconch whorl and is slightly down-tilted, but in some species it is strongly exsert (Clypeostoma salpinx, Pholidotrope gloriosa, Perrinia konos) or slightly sunken below the level of the first teleoconch whorl rendering the apex truncated (Danilia spp., Perrinia angulifera, Vaceuchelus cretaceus).
Microsculpture (Fig. 2) Teleoconch microsculpture within the Chilodontidae appears to show distinct juvenile and adult facies, both of which reveal commonly occurring features that warrant further study as characters of potential phylogenetic significance. The spiral cords of most chi lodontid taxa develop only during the second and third teleoconch whorls, and the first whorl is for the most part sculptured only by axial pliculae. Between these there is often an unusual vermiform microsculpture of fine, broken, wavy and frequently bi furcating, spiral threads which continues onto the second and sometimes subsequent whorls ( Fig. 2A). Although this is cannot be said to be a ubiquitous feature in the Chilodontidae, it is nonetheless common within local representatives of the group, occurring in species belonging to Ascetostoma, Clypeostoma, Danilia and Herpetopoma and has been illustrated in other chilodontids by Marshall (1979: fig. 2h), Moolenbeek & Faber (1989: figs 12, 13) and Engl & Rolán (2009: figs 6, 11). Hickman (1998) indicted that this microsculpture is present from the first appearance of the group in the fossil record (Early Mesozoic).
Microsculptural details are not always evident and may be effected by a number of parameters. Firstly, wear, which removes fine sculptural details, although in live-collected shells this usually only effects the apical whorls (and thus the juvenile microsculpture), and some part of the adult shell generally remains unworn. Secondly, encrustations can also obscure superficial details and this is particularly so in chilodontids, which are frequently encrusted with sponges or coralline algal growths, in the case of sponges sometimes almost completely so (e.g. Ascetostoma providentiae and Clypeostoma salpinx). Thirdly, several taxa have a particularly well developed intritacalx, which instead of being grain-like, occurs as a thick chalky layer obscuring all microsculptural details (e.g. Herpetopoma helix and Vaceuchelus cretaceus). In such cases microsculpture is evident only after ultrasonic cleaning, although the extent to which such treatment might also effect the microsculpture itself is not clear. Radula (Fig. 3) The chilodontid radula is not simple to interpret. Unlike that of many other vetigastropod groups such as the Fissurellidae, Solariellidae and Trochidae, it is difficult to prepare for SEM. The marginal teeth are long and fine, and naturally tend to fold inwards, overlapping each other and the central radula field, and thus obscuring the rachidian and lateral teeth. Careful micro-manipulation of the radula is needed during the final drying stages in order to splay the marginal teeth outward. A further complication is that the differentiation between the lateral and marginal series is not always clear, the tran sition from one to the other being somewhat gradual.
Illustrations of chilodontid radulae were given by Troschel (1879, Euchelus), Hutton (1883, Herpetopoma), Odhner (1917, Hybochelus), Thiele (1924, Euchelus, Danilia and Granata), Cotton (1946, 1959, Granata andHerpetopoma), McLean (1970, Mirachelus), Olsson (1971, Turcica), Beu & Climo (1974, Danilia), Quinn (1979, Mirachelus) and Guidastri et al. (1984, Danilia and Putzeysia). More recently, radula morphology within the group as a whole was discussed and summarised by Hickman and McLean (1990) who used radula characters exclusively in their diagnosis of the subfamily Eucyclinae. Amongst the most significant features noted were the so-called 'hooded' rachidian, complexly interlocking lateral tooth bases, rectangular lateromarginal plate and broad, mitten-shaped outermost marginal tooth. The expanded lateral flanges on the rachidian shaft (the 'hood') and the interlocking of lateral tooth bases are clearly evident in the taxa examined here (Fig. 3A, D). A broad outermost marginal tooth is also present in many of the local species (Fig. 3B), but it seems not to be as large as that illustrated for Turcica (Olsson 1971;Hickman & McLean 1990) and Bathybembix (Hickman 1981). These teeth are generally difficult to see, often being obscured by the reflected un derlying lingual membrane. In contrast, I have been unable to identify a rectangular latero-marginal plate in any of the species examined in this revision, and such has not been mentioned by the earlier authors cited above. Odhner (1917) considered the fourth lateral tooth of Hybochelus mysticus to be vestigial and transitional, but in his drawing this tooth is far from vestigial and retains a serrated cusp. In reality, Hickman and McLean (1990) illustrated latero-marginal plates in a species of Calliotropis and in view of our enhanced understanding of the classification of their 'Eucyclinae' it may be that latero-marginal plates are restricted to the Calliotropidae. Similarly, since Turcica is also now thought to belong to the Calliotropidae (Kano et  al. 2009), the ex tremely large, mitten-shaped outermost marginal tooth may also be a character more distinctive of the Calliotropidae than the Chilodontidae, in which the distal portion of the outermost marginal, though broadened, is not as massively enlarged. A similar expansion of this tooth is evident in some Scissurelloidea (Høisaeter & Geiger 2011;Luque et al. 2001), suggesting that it may be a more widespread, but seldom recorded feature in the Vetigastropoda. Where possible I have examined the radula of at least one species in each genus to provide information on intergeneric variation in radula form. The rachidian cusp is generally well developed and the lateral flanges on its upper shaft expanded to create a hood of variable extent. In most genera there is also a conspicuous raised transverse ridge at the base of the rachidian cusp, giving the tooth a distinctly hunched appearance (Fig. 3A, D) (e.g. Ascetostoma, Clypeostoma, Danilia, Herpetopoma, Perrinia and Vaceuche lus). Guidastri et al. (1984) reported the same structure in Putzeysia Sulliotti, 1889, and it is also evident in some calliotropids (Hickman & McLean 1990). This articulates with the similarly shaped posterior border of the base-plate of the tooth in front. Commonly, the rachidian cusp is relatively coarsely dentate with a strong, lanceolate or acuminate central denticle and 3-5 smaller, also lanceolate, lateral denticles on each side (Fig. 3A, D, E) (e.g. Ascetostoma, Clypeostoma, Danilia, Herpetopoma, Perrinia, Vaceuchelus herein, and Mirachelus (McLean 1970;Quinn 1979)), but in Granata (Fig. 3C) the rachidian cusp is narrowly triangular and its lateral margins finely serrate toward the base (also illustrated by Thiele 1924 andHickman &McLean 1990). A coarsely dentate rachidian cusp morphology is also found in some seguenziids (Marshall 1991, subfamily Asthelysinae and tribe Fluxinellini), suggesting that this commonly occurring character state in the Chilodontidae may be the ancestral condition.
Within row interaction of the tooth bases is complex in the central field, with extensive tooth overlap (Fig. 3A, C, D). The cusp of the innermost lateral is usually similar in size or slightly larger than that of the rachidian, with those of the remaining laterals being similar in size or progressively decreasing slightly in size (rarely the reverse). The shaft of the lateral teeth comprises a thickened median pillar, usually straight, but set at an angle to the long axis of the radula, with an alate flange on both margins, that on the inner margin slotting behind the median pillar of its inner neighbour, that on the outer margin lying behind the inner flange of its outer neighbour (Fig. 3A). The cusp of these teeth is generally obliquely trigonal and rather coarsely dentate, with the central denticle often spathulate, but in Granata the cusps are less oblique and, like the rachidian, finely serrate (Fig. 3C). In Danilia (Fig. 3D) the lateral tooth cusps are strongly asymmetrical, finely serrate on the inner margin and more coarsely dentate on the outer margin (also illustrated by Thiele 1924 andClimo 1974). The transition from the lateral series to the marginal series is moderately clear in some genera (e.g. Herpetopoma and Vaceuchelus, though not in all species), but in others (e.g. Clypeostoma and Granata) there is no clear-cut boundary and determining the number of lateral teeth is therefore difficult. Whether the fourth tooth is considered a lateral or a marginal is open to question in these genera. Many authors have cited the number of pairs of lateral teeth in chilodontid taxa as four (e.g. Odhner 1917;Thiele 1924Thiele , 1929Cotton 1946;Beu & Climo 1974;Quinn 1979;Guidastri et al. 1984), but others have cited three (e.g. McLean 1970;Bandel 2010) and some Vaceuchelus species evidently have only two (see below). However, I am not inclined to put much emphasis on this character for several reasons. Firstly, because it is often somewhat subjective to determine; secondly, because it is likely to be influenced by the size of the species (hence some small Va ceu chelus species with only two pairs of laterals); and thirdly, in one species where the transition is clear (Herpetopoma scabriusculum), I observed one individual with three pairs of laterals and another with four. The character is thus also individually variable.
The marginal teeth are numerous, but the precise number is difficult to establish. In Herpetopoma and Vaceuchelus, though long and slender, they remain relatively robust (Fig. 3E), but in some other genera the marginals are even more elongate and fine, particularly so in Danilia in which all the marginal teeth are extremely slender and delicate (Fig. 3F), appearing as a mop-like mass along the radula margin (described as a 'hairy rope' by Beu & Climo 1974). The inner marginals are coarsely dentate or pectinate along their outer margin in most genera, particularly Herpetopoma and Vaceuchelus, and the denticles may extend some way down the shaft. However, in Clypeostoma and more so Danilia, the dentition on these teeth is finer. As mentioned above, the marginal teeth at the end of the series, particularly the outermost one, have a broader, more spathulate cusp with a finely dentate, almost feathered margin (Fig. 3B). Another unusual feature of the Danilia radula is the buttressed outer shaft base of the inner marginals and its raggedly dentate edge (Fig. 3F). There is also some evidence of this in Perrinia, and it may be a more widely occurring, but seldom visible feature.
In calliotropid taxa, judging by the illustrations given by Hickman and McLean (1990), the rachidian is narrower and has a smaller cusp relative to the laterals, but it retains a well-developed hood and has a particularly strong transverse ridge at the cusp base. Only three pairs of lateral teeth are present and they increase markedly in size from first to third (something not seen on chilodontids). The marginal series is clearly distinct from the lateral one and there is an intervening latero-marginal plate. By comparison with chilodontids, the marginals are considerably less numerous. However, Hickman and McLean (1990) only illustrated the radula of Calliotropis species and how reflective these are of other calliotropid taxa is unclear. If, as molecular data suggests, genera such as Turcica are calliotropid rather than chilodontid (Kano et al. 2009), then radula form in calliotropids is certainly more diverse than is evident from Calliotropis species alone.
Operculum ( Fig. 4) The chilodontid operculum is thin, corneous and generally multispiral. In Euchelus, however, Pilsbry (1890Pilsbry ( in 1889Pilsbry ( -1890 noted that the operculum is of few whorls and he likened it to that of Littorina, using this as a character separating Euchelus from Herpetopoma, which he stated possessed a conventionally multispiral operculum. Beu and Climo (1974) discussed the matter further in relation to the genus Danilia and confirmed that the Euchelus operculum is indeed paucispiral like that of Littorina. This, however, is an oversimplification, for whilst the operculum of Euchelus has a long growing margin and thus relatively few whorls, it is not as paucispiral as that of littorinids and has a noticeably less eccentric nucleus (compare Figs 4A and 4B). In reality, the Euchelus operculum represents a well-developed example of a trend, common in chilodontids, towards the reduction in the number of opercular whorls, particularly in comparison to trochoidean taxa (Hickman & McLean 1990). This trend is also evident in the Seguenziidae (Marshall 1983;Quinn 1983).
The coiling of the operculum is usually tight initially, but the outermost whorls ex pand somewhat more rapidly and the growing margin is correspondingly broader. Ul timately, as in Euchelus, the angle of accretion becomes almost tangential to the pre ceding opercular whorl and the growing edge is long. Operculum form in the taxa Fig. 4 (Fig. 4C), but the gradations are relative rather than categorical. Of necessity, as the rate of whorl expansion increases, the nucleus of the operculum becomes increasingly eccentric. Hickman and McLean (1990) observed that opercular development in chilodontids does not always keep pace with growth of the shell (aperture), noting that the operculum in Granata it is vestigial. My own observations on Granata sulcifera indicate that its operculum, though it does not completely close the shell aperture, is not truly vestigial, its diameter equalling approximately half that of the aperture. In G. imbricata it is considerably smaller, relative to the aperture, but still not vestigial when compared to the miniature operculum of the similarly shaped stomatelline trochid genus Pseudostomatella (Herbert 1998).
External anatomy (Figs 5, 6) Hickman & McLean (1990) and Hickman (1998) have summarised the basic features of the external anatomy of chilodontid taxa, building upon earlier descriptions provided by Beu & Climo (1974) and Guidastri et al. (1984). Judging from the species examined in this study, although the basic ground plan is similar, there is considerable variation in detail. However, since these details are largely available for only one species in each genus, it is not possible to establish whether the features reported here are broadly characteristic for the respective genera as a whole.
Cephalic lappets are present, the free margin ranging from finely digitate to microscopically fimbriate. The cephalic tentacles are well developed and micropapillate. The eyes are prominent, on short stalks not fused to the cephalic tentacles; the eye itself is subterminal and black. Immediately behind the right eyestalk, sometimes appearing to arise from its base, is a post-ocular peduncle. This may be nearly as long or longer than the eyestalk and is not micropapillate, but it is often slightly expanded and flattened distally, and a dorsal longitudinal groove is frequently evident. It is present in both  (Melvill, 1909) sexes. An additional very small process, the subocular tentacle is occasionally present pro jecting from beneath the base of the right eyestalk (e.g. in Granata, see below and Kano 2008). The snout is often pigmented, has extensive ventro-lateral flanges and the ventral lip is deeply split in the mid-line.  (Melvill, 1909); (B) Clypeostoma salpinx (Barnard, 1964); (C) Danilia textilis sp. n.; (D) Granata sulcifera (Lamarck, 1822); (E) Perrinia angulifera (A. Adams, 1853); (F) Vaceuchelus cretaceus sp. n.; (G) V. natalensis (Smith, 1906).
The neck lobes are not fused to the eyestalks, arising instead adjacent to and overlapping the snout flanges, below the cephalic tentacles. Both neck lobes are well developed, the free margin microscopically fimbriate and bearing a series of micro papillate tentacles often of two or three size ranks. There is considerable variation in the number and arrangement of the neck lobe tentacles between genera. Commonly these arise from just under the lobe margin. Similar tentacles occur posteriorly along the length of the epipodial fold, the number depending on the size of the species and the individual. Again there are two or three size ranks. In Ascetostoma, Clypeostoma, Gra nata and Perrinia there are minute tentacles between the larger tentacles, but these are absent in Danilia and Vaceuchelus. Free-standing, mushroom-like epipodial sense or gans such as occur in many trochiodean genera are not evident, even beneath neck lobes, but most of the larger epipodial tentacles have a basal swelling on the ventral side which probably represents an epipodial sense organ. Similar swellings are sometimes evi dent at the base of the larger neck lobe tentacles and Danilia possesses several distinct sense organs on the underside of its neck lobes.
The ctenidium is bipectinate with a short afferent membrane and thus the free portion is long. The right hypobranchial gland is well developed and trigonal in shape, surrounded on two sides by the rectum which loops around its left margin. In Granata the gland is particularly large, ovate to kidney-shaped, with the rectum curving around the left side. It is responsible for producing the foul-smelling, milky secretion that is emitted when animals of this genus are disturbed (Hickman 1998, and pers. observ.). The rectum is generally turgid, filled with a longitudinally ridged faecal string composed of amorphous microscopically particulate faecal material. It extends further forward than is the case in trochoidean taxa, almost reaching the anterior right extremity of the mantle edge. Distally it is free of the mantle cavity wall and tapers to form a nozzle, the tip of which frequently possesses a minute tentacle-like appendage.
The presence of a post-ocular peduncle in chilodontids is a significant feature and one reflective of their seguenzioidean affinity (Kano 2008). This is distinct from, and should not be confused with, the subocular tentacle, a structure found also in many Trochoidea. The function of the post-ocular peduncle is unclear, though a penis-like role as a conduit for sperm transfer during pseudo-copulation has been suggested for a similar structure found in calliotropids (Dall 1889). If such is the case, then its presence in both sexes is puzzling and requires an explanation -something that has not yet been provided. Similar structures are evident in other vetigastropods, some present only in males, but care needs to be taken before inferences relating to the function of these structure and the phylogenetic implications of their presence are drawn, since their structure has not been investigated in detail and their homology has not been demonstrated.

BIOLOGY, ECOLOGY AND ZOOGEOGRAPHY
Chilodontid gastropods inhabit a considerable depth range, from the intertidal zone (e.g. Euchelus, Granata, Herpetopoma and Vaceuchelus) to depths of 2000 m (Danilia) or more (Putzeysia). However, despite the fact that some species are intertidal and may even be common, the biology of the family as a whole is poorly known. The group is thought to have arisen in the Early Mesozoic of Europe, and to have subsequently radiated in the Cretaceous, both in terms of diversity and geographic range (Hickman & McLean 1990), in association with the contemporaneous expansion of the carbonate-based habitats on which they lived. Today the greatest diversity, at both genus and species level, remains associated with warm water and hard, carbonate-based substrata, as evidenced by the rich chilodontid fauna of the Philippines Poppe & Tagaro 2008) and the central Indo-West Pacific in general. Mostly this fauna occurs in near-shore and continental shelf ecosystems (<200 m). The greatest depth at which living specimens have been found in the south-western Indian Ocean is 277 m (Clypeostoma salpinx; Table 1). Such is in marked contrast to the Calliotropidae, which are largely bathyal (>200 m), and are associated with unconsolidated substrata and colder water (including the Antarctic).
Consistent with the above, the Chilodontidae is clearly a tropical element within the fauna of the south-western Indian Ocean. Only one species, Vaceuchelus gemmula, ranges beyond the subtropical waters of the east coast of South Africa in to the warmtemperate waters of the southern Cape. This is also the only chilodontid endemic to South Africa. A considerable portion of the regional chilodontid fauna (14 out of 27 re corded species, 51.9 %); however, is endemic to the south-western Indian Ocean (Table 1), indicating a significant focus of endemism in this part of the Indo-West Pacific. This may be due to the prevailing south-westerly current regime, which would tend to restrict nascent taxa to this region. A further five species (18.5 %) are endemic to the western Indian Ocean and eight (29.6 %) are more widespread Indo-West Pacific taxa ranging east to south-east Asia. Interestingly, for some of the regionally endemic species there is a closely similar species occurring in the central Indo-West Pacific, suggestive of a sister taxon relationship spanning the Indian Ocean (e.g. Ascetostoma providentiae and A. ringens, and Vaceuchelus cretaceus and V. pagoboorum).
Almost without exception, the chilodontids of the south-western Indian Ocean are associated with hard substrata (Table 1). Commonly these are carbonate-based, but some species occur in habitats lacking and obvious carbonate facies, such as the rocky shore of KwaZulu-Natal and Eastern Cape (Vaceuchelus natalensis and V. gemmula), and the sponge-dominated communities on the edge of the continental shelf in the same region (Clypeostoma salpinx and Danilia textilis). The latter communities, however, often contain a significant octocoral and scleractinian component. Only one species, Granata sulcifera, occurs in habitats dominated by soft substrata, and can be found in sheltered bays with muddy sand, but even here it lives attached to hard objects. This species evinces a somewhat limpet-like mode of life that is taken further by the Australian G. imbricata, which clings tenaciously to the rocks on which it lives and is unable to right itself once dislodged (Hickman 1998). Both species are negatively phototropic and secrete a foul-smelling, milky mucus when disturbed (see external anatomy above), as evidently does G. lyrata (Kano 2008). Unlike G. imbricata, however, G. sulcifera has no difficulty righting itself if upturned, using the highly mobile and extendable an terior portion of the foot.
Almost nothing is known of their diet, though one may speculate, given the robust interlocking of the teeth in the central field of the radula, and the generally strong dentition of the rachidian and lateral tooth cusps, that they graze superficially on the hard substrata on which they occur and on the organisms growing thereon, the long marginal teeth being used to gather up dislodged material. The unusual marginal teeth of Danilia species, however, are suggestive of a more specialised diet, perhaps associated with the deep-water corals with which they commonly co-occur.
As is to be expected in vetigastropods the sexes are separate in chilodontids, but little is known of their reproductive biology. Duch (1969) recorded that in the littoral Euchelus gemmatus (Gould, 1845) (probably a species of Herpetopoma) spawning is associated with the spring equinox and is initiated by pair formation, subsequent to which gelatinous egg masses are deposited on hard surfaces, inside which the embryo grows into a fully developed veliger that hatches as a 'semi-crawling larva' after 1-2 weeks. One may assume, therefore, that, in this species at least, a free-swimming stage, if such exists at all, is at most brief. Such may not be the case in other species, particularly those that possess a prominent beak on the protoconch lip (e.g. Clypeostoma salpinx and Granata sulcifera), suggesting, as mentioned above, a longer, more active swimming phase. In life, the shell of many species is covered, often entirely so, with a living encrusting sponge, particularly in Euchelus and Herpetopoma (Odhner 1917;Gardner 1975;Walsby & Morton 1982;Hickman & McLean 1990;Wilson 1993;Poppe et al. 2006;Poppe & Tagaro 2008). Others commonly have superficial growths of white or pink encrusting coralline algae. TAXONOMY Family Chilodontidae 1 Wenz, 1938 The use of generic names now considered to belong to the Chilodontidae has been complicated by a lack of precision. Doubtlessly, in many cases this is due to the fact that the type species are poorly known and thus the diagnostic characters of the genera are not clearly identified. Genera such as Turcica (sensu stricto, a calliotropid genus) and Euchelus have been employed as hold-all taxa that in reality represent ill-defined assemblages of dubiously related species. Some clarity is beginning to emerge as more material is studied, but there remain problematic areas where shell characters, when considered across a range of taxa, seem to intergrade between genera, as for example between Euchelus and Herpetopoma. Even within Herpetopoma there is a puzzling diversity of shell form, which suggests that it may be a composite taxon (see below). I propose two new genera for taxa which exhibit distinctive combinations of characters not present in the existing genera. A third new genus is proposed for extant species cur rently referred to Agathodonta, a fossil genus that I consider is not appropriate for these Recent forms.
The genera are not treated alphabetical order, but are grouped loosely in terms of si milarity in shell form. However, this should not be taken to indicate any suggestion of phylogenetic relationship. Such inferences must await analysis of molecular data and a more complete dataset of morphological characters. Species treatments do not contain diagnoses as these tend to be repetitive of information given in the description. Instead, I provide keys to species which summarise the characters important for species discrimination and represent a more useful tool for identification. Further discussion of distinctive features and comparison with similar extralimital species is provided under 'Remarks'. In addition to the Recent species discussed, I draw attention to a fossil taxon Chilodonta (Agathodonta) africana described by Rennie (1930)  Excluded taxa Leptothyra alfredensis Bartsch, 1915, and Cyclostremella alfredensis Bartsch, 1915, both from Port Alfred, Eastern Cape, superficially resemble Vaceuchelus, but show much greater similarity to the skeneid genus Parviturbo Pilsbry & McGinty, 1945(Hick man & McLean 1990Warén 1991). Unfortunately, this cannot be confirmed by examination of the radula, as neither species has ever been found alive. Both names may quite possibly apply to the same species. Likewise Vitrinella agulhasensis Thiele, 1925, from the Agulhas Bank, resembles Vaceuchelus, but is also probably a species of Parviturbo.
Stomatella cancellata Krauss, 1848, the type species of Hybochelus Pilsbry, 1890, was erroneously described from Table Bay, Cape Town. The species is not part of the southern African fauna and occurs instead in the central Indo-West Pacific (Wilson 1993;Herbert 1996;Herbert & Warén 1999;Poppe et al. 2006;Poppe & Tagaro 2008).
Material referable to Tibatrochus Nomura, 1940 has been dredged off southern Mozambique and north-eastern South Africa, but is not included in this review as I strongly suspect the genus belongs in the Calliotropidae.
Key to genera of Chilodontidae in the south-western Indian Ocean (applies only to specimens with mature apertural dentition)  Barnard, 1964. Diagnosis: Shell moderately elevated; spire whorls flat-sided to weakly convex; suture indented, level with subperipheral cord; sculpture of spiral cords and axial pliculae, cords ornamented with squamose beads where crossed by pliculae; aperture subcircular to obliquely D-shaped; outer lip conspicuously flaring beyond an internal collabral thickening; columella stout and bearing 2 rounded teeth when mature; thickened interior of outer lip with ridge-like denticles, that nearest columella largest and separated from basal columella tooth by deep U-shaped notch; umbilical and parietal region covered by glossy inductural callus shield; shield raised and flaring basally where it joins basal lip; umbilicus absent; circumference of aperture and inductural shield more or less in one plane, obliquely tangential to base of last adult whorl; outer lip not thickened externally; protoconch exsert and with a distinct sinusigera-like projection on terminal lip. Remarks: Extant species belonging to this genus have previously been referred to Agathodonta Cossmann, 1918(McLean 1984Neubert 1998;Vilvens 2001;Vilvens & Héros 2003;Poppe et al. 2006). The type species of Agathodonta, by original designation, is Trochus dentiger d'Orbigny, 1843 (an unjustified emendation of Trochus dentigerus d'Orbigny, 1843) from the Lower Cretaceous (Neocomian) of north-eastern France, which has recently been shown to be a junior synonym of Littorina elegans Deshayes in Leymerie, 1842 (Kollmann 2005). Whilst extant species undoubtedly exhibit some similarity with Agathodonta, examination of the lectotype (designated by Kollmann 2005: 70, pl. 9, fig. 6) and topotypic material of Trochus dentigerus (UCBL, Fig. 7A, B and MNHN, Fig. 7C, respectively) indicates that its shell has more strongly convex whorls, does not develop a flaring aperture or expanded inductural callus shield, has a broad, thickened external varix behind the outer lip, with additional varices on the spire whorls (arrowed in Fig. 7A, C), shows little evidence of any denticles or ridges inside the outer lip, and the columella teeth, instead of being discrete teeth (which develop only at maturity), appear to be the ends of ridges spiralling up the columella. In addition, the sculpture is considerably less coarse, the spiral cords being finely and regularly beaded, and without axial pliculae in their intervals. Since these characters are at variance with those of Recent species, I have chosen not to refer extant material to Agathodonta. The original figure of Trochus dentigerus provided by d'Orbigny (1843) is misleading in not showing the varices (Fig. 7D), but Cossmann's figures clearly do so, though strangely he does not mention them in his description of the genus (Cossmann 1918: pl. vii, fig. 9). Such varices also occur in Calliovarica Vokes, 1939, which is also probably referable to the Chilodontidae (Beu & Raine 2009).
Since no other genus-rank name is available for these extant species, I propose the new genus Clypeostoma, with Turcica salpinx Barnard, 1964, as type species. Other described taxa referable here are Agathodonta elongata Vilvens, 2001, A. meteorae Neubert, 1998, A. nortoni McLean, 1984, Euchelus townsendianus Melvill & Standen, 1903 and perhaps Perrinia cecileae, P. docili and Herpetopoma barbieri all of Poppe, Tagaro & Dekker (2006). Whereas Clypeostoma elongatum, C. reticulatum and C. salpinx are distinctive, the others are confusingly similar and exhibit intergrading variability, suggesting that some at least may prove to be synonyms (see below). When a good series of samples is available for one taxon, e.g. C. salpinx, it is clear that allowance must be made for some individual variation in size at maturity, L/D ratio, spiral cord number and strength of apertural dentition. In the absence of such information for the other taxa, it is not possible to make informed comment on potential synonymies within the genus. In some cases the differences evident between the species are small and perhaps of limited significance. C. meteorae and C. townsendianum were both described from the mid to outer continental shelf of the north-western Indian Ocean and may well be synonyms, even though the holotype of former is smaller than the figured syntype of Euchelus townsendianus (length 7.5 vs 10.4 mm), which I here refigure and designate as lectotype (Fig. 12F, G).
Clypeostoma differs from Danilia in lacking an external varix behind the outer lip and in not having a sunken region median to the thickened edge of the columella pillar. In Danilia the shell apex is also truncate and the protoconch flat or a little sunken. In Ascetostoma gen. n. the apertural dentition is more complex and the umbilicus is retained and lined with callus. Some species referred to Herpetopoma Pilsbry, 1890, also have a strong U-shaped notch at the base of the columella, but such species have only one distinct columella tooth, lack an expanded inductural callus and often retain an open umbilicus.
Key to species of Clypeostoma in the south-western Indian Ocean 1 Columella teeth well developed, of more or less equal size (though not necessarily the same shape

Description:
Shell: Large for the genus (length up to 16.7 mm), trochoid-turbiniform, with conical spire and relatively deep, globose last adult whorl (L/D=1.38-1.44, last adult whorl 0.70-0.74 of shell length); teleoconch of up to 6 whorls; first two whorls rounded, whorls 3-4 more or less flat-sided, subsequent whorls convex; apical angle 69-74°; suture of spire whorls level with and mostly covering subperipheral cord of preceding whorl, demarcated by a well-developed channel below peripheral cord; shell periphery cf. nortoni (circles), C. reticulatum (cross) and C. salpinx (triangles). Each symbol represents one or more records.
rounded. First teleoconch whorl worn in all available specimens, but traces of curved axial pliculae remaining; 3 spiral cords arise during second whorl, with a fourth appearing below adapical suture toward end of whorl; abapical (peripheral) cord strongest; cords crossed by axial pliculae and beaded at intersections; a fifth cord arising below subsutural cord during third whorl (sometimes a sixth during fourth whorl), penultimate whorl thus with 5-6 spiral cords, an additional cord becoming evident level with abapical suture; sculpture remaining similar but strengthening on fourth and subsequent whorls; beads on subsutural cord developing in to angular nodules (25-30 on last adult whorl); intervals between cords slightly wider than cords themselves (that below peripheral cord widest) and crossed by axial pliculae creating quadrate interstices; alignment of pliculae from interval to interval somewhat variable and irregular due to intercalation of additional pliculae, but general pattern of sculpture clearly reticulate, particularly on spire whorls; beads stronger and axially elongated on latter part of last adult whorl; sutural cord of spire whorls may emerge above suture toward end of last adult whorl. Base rounded with 4-6 spiral cords, the last small and partly concealed by reflected lip of aperture; basal cords somewhat more finely beaded than those above periphery. Peristome markedly oblique, more or less in one tangential plane; aperture subcircular to roundly quadrate; columella lip robust, with 2 relatively massive teeth, the upper one slightly more robust, the lower one somewhat narrower and with a small denticle on its lower margin; parietal and umbilical region covered with well-developed, glossy callus which flares outward over base; callus porcelaneous and mostly smooth, but with some beads of unequal size in region adjacent to columella teeth; one particularly strong bead at base of lower columella tooth; edge of callus raised and flaring where it joins flared margin of outer lip. Outer lip lacking an external varix, but somewhat thickened internally and strongly flaring, with 9 labral denticles; denticle nearest base of columella largest and peg-like, separated from basal columella tooth by a U-shaped notch; remaining labral denticles representing the ends of in-running spiral ridges extending deep into aperture, where there may be additional intermediary ridges; similar ridges present inside parietal portion of aperture; denticle at end of uppermost labral spiral ridge comprises a somewhat disjunct swelling, itself with 2 or 3 smaller granules; ridge below this ending in a single large elongate denticle. Microsculpture: No fresh material available; all traces of intritacalx lost, but some evidence of scratch-like microsculpture present on later whorls.
Protoconch: Missing in all available specimens. Colour: Shell mostly uniform cream-white to dirty buff, with some pale orange-brown spotting, particularly on subsutural and basal cords.
Operculum, radula and external anatomy: Unknown.  (Fraussen & Rosado 2011). Remarks: This species is distinctive amongst south-western Indian Ocean chilodontids on account of its relatively large size, coarse sculpture and well-developed apertural dentition. The most similar species is Clypeostoma elongata (Vilvens, 2001) from Indonesia and the Philippines, but that species is still larger (adult length over 19 mm), has a more acute apical angle (<60°), a less rounded last adult whorl and only four spiral cords on the spire whorls. In addition, the aperture is transversely elongate and the lower columella tooth is larger than the upper one and bears additional denticles. C. reticulatum shows some variation in the strength of the sculpture (coarseness of reticulation), but this may in part be caused by damage to the outer lip during growth and the subsequent intercalation of additional spiral cords.
That this species has not been found off the Zululand coast of South Africa, a relatively well sampled area not far removed from the type locality, indicates that the isolated Almirante Leite Knolls (a volcanic seamount with numerous craters, rising from -1100 to -80 m) provide habitats of a different nature to those occurring on the continental shelf and upper slope. The station from which this material was obtained also contained an undescribed species of Bolma (Alf et al. 2010) and two new buccinid species (Fraussen & Rosado 2011), and many other new species of benthic invertebrates have been obtained from the locality as a whole (Bouchet pers. comm.), some of which have already been named (Cabezas et al. 2010;Komai & Chan 2010;Richer de Forges 2010).
scale-like nodules where crossed by pliculae, those on uppermost (subsutural) cord frequently larger; intervals between cords slightly wider than cords themselves; cord intervals on last adult whorl occasionally with a weak intermediary cord. Base rounded, sculptured with ±6 spiral cords; cords somewhat weaker than those on apical surface, but similarly nodose; umbilicus closed in all but small juveniles (<4 whorls). Peristome markedly oblique, more or less in one tangential plane; aperture subcircular to D-shaped, flattened in the parietal region; columella lip with 2 teeth, the lower one well developed, the upper one less so; teeth bluntly rounded, separated by shallow concavity; parietal and umbilical region covered with well-developed, translucent, smooth, glossy callus; margin of callus raised and flaring basally, running smoothly into basal lip; callus with 1 or 2 small tubercles near base of lower columella tooth. Outer lip lacking external varix, but thickened internally and bearing up to 15 denticles; denticles ridge-like, more or less in a single row and usually alternating in strength, that nearest columella usually strongest and separated from basal columella tooth by a U-shaped notch; edge of outer lip flaring; interior highly nacreous, not spirally lirate (except at apertural thickening), but somewhat angled beneath cords of external surface. Microsculpture ( Fig. 11B, C): Early teleoconch whorls with vermiform spiral threads in intervals between axial pliculae; adult microsculpture of scratch-like marks, filled with intritacalx in fresh specimens, but this seldom well developed and usually obscured by superficial encrustations. Protoconch (Fig. 11A, C): Translucent white to pale buff; diameter 360-380 μm; glo bose, strongly exsert and somewhat tilted; terminal lip convex with sinusigera-like beak in mid region; surface sculptured with a fine irregular granulation and a faint spiral thread midway between sutures. Colour: Shell mostly uniform buff to pale orange-brown, occasionally nearly white; cord intervals with slight pink/green iridescence; some specimens with occasional slightly darker spots and blotches beneath suture and at edge of outer lip; live-collected specimens nearly always over-grown with a thin encrusting sponge (Fig. 10E, F).
Radula (Fig. 11D, E): Formula ∞+3+1+3+∞, with ca 80 transverse rows of teeth; tran sition from lateral to marginal series not clearly defined. Rachidian shaft with welldeveloped lateral flanges creating a distinct hood, base of cusp with raised, transverse basal ridge, cusp apex acutely trigonal with a narrow median denticle and 3-5 smaller denticles on each side. Lateral teeth overlapping extensively, their cusps asymmetrically trigonal; central denticle large on first lateral, progressively decreasing in size on second and third; side denticles few on first lateral, but progressively more numerous on laterals 2 and 3. Marginals numerous, the inner ones slightly longer than the laterals, their tips relatively narrow and finely pectinate laterally; marginals progressively longer and more slender in middle of series then shorter with proportionately broader tips at radula margin.
External anatomy (Fig. 6B): Body uniformly yellowish white, no skin pigmentation evi dent in preserved specimens. Cephalic lappets well developed, almost meeting in mid-line, free margin with fine projections; right post-ocular peduncle present in both sexes, nearly as long or longer than eyestalk, with a faint dorsal groove, peduncle tip often flattened and expanded; no right subocular tentacle evident; snout with extensive ventro-lateral flanges extending well beneath neck lobes, mouth deeply split midventrally; neck lobes broad, anterior two-thirds of right lobe with approx. 5 first-order tentacles with many smaller intermediaries, posterior third minutely fimbriate; anterior three-quarters of left lobe with approx. 10 tentacles in a variety of sizes, posterior quarter more or less smooth; epipodium bearing approx. 7 relatively large, first-order tentacles (not all the same size) with many, very much smaller intermediaries; larger epipodial tentacles usually with an indistinct basal sense organ; no epipodial sense organs evident beneath neck lobes.
Type material: Two syntype lots of Turcica salpinx Barnard, 1964 (SAMC) XX115, 9.vii.1986 (D4231); ditto (29.8400°S 31.2333°E), living, -150 m, sandstone gravel and some sponge, dredged NMDP, RV Meiring Naude, st'n XX114, 9.vii.1986 (D4146); off Umlaas Canal (30.0133°S 31.0600°E), -150 m, muddy sand and fine pebbles, dredged NMDP, RV Meiring Naude, st'n XX75, 10.vii.1985; ditto (30.0183°S 31.0533°E), living, -150 m, coarse sand and pebbles with numerous spatangoids, dredged NMDP, RV Meiring Naude, st'n XX70, 9.vii.1985  Type locality: Barnard's type material originated from two Pieter Faure stations, but he did not select one in particular as the type locality. The given data for one of these sta tions (off Hood Point (East London), 49 fath. [-90 m]) has since been shown to be er roneous (Herbert 1987: 344). In this instance, the Hood Point locality is not far out of the known range of the species, but for other taxa it is widely so. The dredge haul was more probably taken off Durban. In view of this inaccuracy I here select the provenance of Barnard's other type lot, off Cape Morgan [close to mouth of Great Kei River] 77 fath. [-141 m], as type locality. Distribution and habitat ( Fig. 8): South-eastern Africa; from southern Mozambique (Inhambane) to the Great Kei River, Eastern Cape, South Africa; -60-400 m, living specimens -60-277 m, on hard substrata with abundant marine growths, particularly sponges. Remarks: When compared to other species here transferred to Clypeostoma, C. salpinx differs from C. meteorae, C. nortoni and C. townsendianum in having slightly flatter whorls, commonly four rather than five or six spiral cords above the suture, fewer tubercles on the callus shield near the basal columella tooth, less elongate, more widely spaced denticles inside the outer lip and a more extensive inductural callus. C. elongata Vilvens, 2001 from Indonesia and C. reticulatum are both considerably larger, have coarser sculpture and more robust columella teeth. Within southern Africa, juvenile C. salpinx may be confused with those of Danilia textilis, but the latter have finer, more regularly cancellate sculpture, a sunken rather than an exsert protoconch and more rounded whorls with a more narrowly channelled suture.
Specimens from the northern limit of the distribution (off Inhambane) are surprisingly small, almost half the size South African specimens (Fig. 10G). However, this is the only significant conchological difference between this material and typical C. salpinx, and I consider it to be insufficient evidence upon which to base the description of a new species. Other species of Clypeostoma also exhibit considerable variation in size at maturity.
Clypeostoma meteorae (Neubert, 1998)  Remarks: Five shells matching the description of this little-known Red Sea-Gulf of Aden species were obtained during dredging surveys undertaken by the MNHN off Madagascar (Campagne Miriky and Exped'n ATIMO VATAE). In this material the aperture is clearly distinct from that of C. salpinx in having stronger columella teeth and a much less extensive inductural callus shield. There are also in-running ridges extending from the labral denticles into the aperture and the callus shield, though less extensive, bears superficial ridges in the parietal region and additional granules, particularly around the columella base. Like the original material of C. meteorae, these specimens have four spiral cords on the spire whorls, but 1-2 intermediary cords appear during the penultimate whorl such that the last adult whorl has 5-6 spiral cords above and including the peripheral one.
In terms of its apertural features, this Malagasy material is also close to C. cf. nortoni (see below) and C. townsendianum, but it is considerably smaller than both. The specimens all have mature apertural dentition and range in length from 5.3-6.9 mm. In addition, the protoconch is also smaller, diameter 220-240 μm (compared to 310-320 μm for C. cf. nortoni). Specimens at the smaller end of this size range show considerable similarity with Perrinia docili Poppe, Tagaro  A number of Clypeostoma shells resembling C. nortoni have been dredged off Madagascar and obtained ex piscibus from the Sofala Bank, off central Mozambique. Similar material evidently also occurs off Réunion and was recorded there by Jay (2009 as Clanculus ceylonicus). Compared with C. meteorae, these specimens are consistently larger (mature length 9.6-14.6 mm) and have a larger protoconch (diameter 310-320 μm). In addition, the basal callus shield is more extensive and smoother, bearing (apart from 3-5 strong, in-running parietal ridges overlying the basal sculpture of the previous whorl) only traces of superficial ridging in the parietal region and a small number of granules associated with the medial columella area. C. townsendianum (Fig. 12F, G), from the Persian Gulf, is of a similar size (figured syntype, length 10.4 mm), but has stronger apertural dentition more similar to that of C. meteorae. The form of the apertural dentition in the present material is closest to that of the Philippine C. nortoni, but the shell attains a relatively larger size (length up to 14.6 mm) than does C. nortoni, and the suture is slightly less indented and the whorls thus less convex. With the limited amount of material available and the geographical distances involved, it is difficult to assess the significance of these differences. I cannot thus confidently identify this material as C. nortoni, but rather draw attention to its existence and its similarity to that species.    (2001) consider O. otaviana to represent a distinct fossil species -an opinion shared by Landau et al. (2003). In such case, the type species of Danilia and Cantraine's Olivia are not the same and they are thus subjective rather than objective synonyms. Keen (1960) listed Heliciella O.G. Costa, 1861, in the synonymy of Olivia, but Beu and Climo (1974) considered the affinity of this taxon with Olivia and thus with Danilia to be debateable, since its type species, H. costellata O.G. Costa, 1861 2 , was based on a very juvenile shell. (The specimen of H. costellata figured by O.G. Costa (1861) has a diameter of 1.0 mm and comprises only approx. 1.5 teleoconch whorls.) They chose instead to employ the younger name Danilia on account of this uncertainty. However, Monterosato (1884) had earlier stated that H. costellata was a juvenile shell of Danilia tinei and certainly the figures of juvenile D. tinei provided by Scaperrotta et al. (2009) clearly support the view that H. costellata is a juvenile Danilia. However, Palazzi and Villari (2001), recognising H. costellata as a species of Danilia, believed it to be distinct from D. tinei and to represent a second Recent European species of this genus. Thus Heliciella and Danilia are evidently synonymous and since both are valid names, the earlier one, Heliciella, ought to be afforded priority. However, in order to maintain prevailing usage, and in accordance with ICZN, Art. 23.9 (ICZN 1999), the principle of priority can be moderated, provided the conditions of Art. 23.9.1.1 and Art. 23.9.1.2 are met. In this regard, I am not aware that Heliciella has been used as a valid name after 1899 (Art. 23.9.1.1) and Danilia has been used more than 25 times in the last 50 years by at least 10 different authors (Art. 23.9.1.2) (Beu & Climo 1974;Powell 1979;Piani 1980;Aimassi et al. 1983;Guidastri et al. 1984;Spadini 1986;Graham 1988;Vaught 1989;Hickman & McLean 1990;Poppe & Goto 1991;Wilson 1993;Giannuzzi-Savelli et al. 1994;Jansen 1996;Millard 1997;Higo et al. 1999;Sasaki 2000;Palazzi & Villari 2001;Vilvens 2001;Spencer et al. 2002;Landau et al. 2003;Rolán 2005;Vilvens & Héros 2005;Poppe et al. 2006;Crocetta & Spanu 2008;Poppe & Tagaro 2008;Kano 2009;Scaperrotta et al. 2009;Spencer et al. 2009;Bandel 2010;De Simone & Kosuge 2010). Some of these, despite recognising the priority of Heliciella over Danilia, have continued to use the latter as the valid name. Therefore, in accordance with Art. 23.9, Danilia is to be afforded priority over the earlier, but unused Heliciella. Danilia thus becomes a nomen protectum and Heliciella a nomen oblitum. Remarks: The genus Danilia is known primarily from relatively deep water and has a fossil record extending back to the Lower Cretaceous (Beu & Climo 1974). Nine Recent species are known from the Indo-West Pacific, eight of which were discussed and illustrated (mostly type specimens) in a useful contribution by Vilvens and Héros (2005). The differences between the species are in some cases small, and Beu and Climo (1974) cautioned that without more detailed comparative study, it is impossible to be certain whether each of these nominal taxa represents a genuinely distinct species, or whether there are fewer, more widespread and sculpturally variable ones -an observation with which I concur. The problem is exacerbated by the fact that most descriptions have been based on very few specimens and thus give no indication of intraspecific variability. These difficulties notwithstanding, I describe below two additional species, since neither appears clearly referable to any of the described taxa.
The radula of Danilia tinei (Calcara, 1839) was illustrated by Guidastri et al. (1984 as D. otaviana) and that of D. insperata was figured and discussed in detail by Beu and Climo (1974). That of D. textilis described below is very similar.
Key to species of Danilia in the south-western Indian Ocean 1 Shell relatively small (adult length <6 mm); spiral cords of unequal size, the two largest delimiting a cylindrical peripheral band; axial pliculae fine, Etymology: Named for Prof. Philippe Bouchet (MNHN), well-known malacologist and co-ordinator of numerous important dredging expeditions.

Description:
Shell: Turbiniform with moderately elevated spire (L/D=1.09-1.14); teleoconch of 4.25-4.5 whorls; apical angle approx. 75°; whorls convex and suture indented, level with periphery on spire, but descending below this just prior to outer lip; protoconch sunken and apex thus appearing truncated; outer lip with well-developed subterminal varix. First teleoconch whorl sculptured with approx. 17 orthocline axial pliculae; 4 spiral cords develop during second whorl (P1-P4); additional secondary and tertiary cords arising during subsequent whorls; abapical cord (P4) strongest; axial pliculae narrow, becoming strongly prosocline on later whorls, the crest crisp and leaning forward; spiral cords beaded where crossed by axial pliculae, beads on primary cords scale-like; last adult whorl with P2-P4 (particularly P3 and P4) stronger than other cords; P3 and P4 delimiting an almost cylindrical peripheral band; subsutural cord (P1) also slightly larger and with angular beads that intermesh in a zip-like manner with beads of peripheral cord (P4) of preceding whorl, delimiting a narrow sutural channel; number of intermediary cords variable, generally only 1-2 between P3 and P4; 5-6 between P1 and P3 (including P2); beading of intermediary cords weaker; cords generally somewhat narrower than their intervals and slightly stronger than axial pliculae; interaction of cords and pliculae producing a fine, regular, oblique cancellation with rhomboidal interstices. Base with approx. 10 spiral cords of alternating size; the second one below peripheral cord generally the strongest; axial pliculae continue onto base rendering basal cords finely beaded. Peristome markedly oblique, more or less in one near-tangential plane; aperture roundly D-shaped and flattened in parietal region; columella lip a thickened pillar set with 2 teeth, lower one a well-developed, rounded peg, the upper one smaller; interval between teeth shallowly concave; umbilical region medial to thickened columella pillar sunken, forming an elongate curved pit, broadening basally; umbilical/parietal region covered by a thin, extensive inductural callus; callus translucent, smooth and glossy, raised somewhat basally and confluent with flaring margin of outer lip; interior of outer lip with an in-set varix lying beneath external outer lip varix; internal varix swollen to form prominent bulge near junction of basal and columella lips, creating deep, U-shaped notch below lower columella tooth; apertural varix set with numerous small, ridge-like denticles, these restricted to varix, not running into deeper portions of aperture; interior of aperture with traces of nacre (specimens not fresh), not spirally lirate, though spiral cords of shell exterior visible by translucence; margin of outer lip flaring; external varix ca 0.25 mm wide and set back a similar distance behind lip edge. Microsculpture: Irregular, vermiform spiral threads present on early whorls; later whorls with evidence of scratch-like sculpture, but sculptural details largely obscured by dirty intritacalx deposit, particularly in interstices.
Protoconch: Present only in holotype; translucent white; diameter 320 μm; sunken into first teleoconch whorl and somewhat tilted; terminal lip evidently more or less straight.
Colour: First teleoconch whorl uniform white, later whorls pale buff with faint brown spots on primary spiral cords; flared outer lip and external varix with brown marks in intervals between paler primary spiral cords. One paratype with darker brown subsutural blotches, stronger spots on the primary peripheral cords and irregular brownish mottling on the base.
Operculum, radula and external anatomy: Unknown. Note: The holotype is the most complete specimen, but its apertural dentition is subadult; one of the paratypes has more mature apertural features (Fig. 14D), but is missing the apical whorls. Distribution ( Fig. 13): Known only from off the coast of the far north of Madagascar, -238-249 m.
Remarks: Danilia boucheti is smaller than any of the other described species of Danilia, most of which attain or exceed 10 mm in length (Vilvens & Héros 2005). Perhaps the most similar species is D. angulosa Vilvens & Héros, 2005 from Melanesia and the Philippines, which is also small (length up to 7.9 mm) and has stronger spiral cords associated with the periphery, creating a cylindrical peripheral band. In that species, however, the cords are stronger than in D. boucheti, the whorls more distinctly shouldered, and there is only one intermediary cord between the shoulder cord (upper pe ri pheral cord) and the subsutural cord. In D. boucheti there are 5 or 6 intermediary cords in this region.
Figs 4E, 6C, 13, 15-17 Etymology: From Latin textilis (woven); in reference to the regular, net-like sculpture. Description: Shell: Trochoid-turbiniform, moderately elevated (L/D=1.10-1.30); teleoconch of 5-6 whorls; whorls rounded, but peripheral spiral cord frequently slightly stronger than others, giving the appearance of a weak peripheral angulation; apical angle approx. 75°; protoconch sunken and apex thus appearing truncated; suture indented, but somewhat adpressed, narrowly channelled, inserted at level of subperipheral cord, but descending below this just prior to outer lip; outer lip with well-developed subterminal varix. First teleoconch whorl sculptured with 15-18 axial pliculae; 4 spiral cords develop during second whorl, others arising by intercalation with growth; penultimate and last adult whorls with ±8 primary spiral cords between suture and periphery (inclusive); cords well defined, narrower than their intervals; an intermediary cord often developing between primary cords in latter half of last adult whorl. Axial sculpture of prosocline pliculae persists throughout growth; pliculae generally slightly weaker than cords, these together producing a regular, oblique cancellation with equilaterally rhomboidal interstices; cords roundly beaded where crossed by pliculae; beads stronger and more angular on subsutural cord and still larger and scale-like or spine-like on peripheral cord. Base with ±7 primary spiral cords, their intervals usually with a weaker intermediary in final half whorl; axial pliculae continue onto base but their number appears to double in latter third of last adult whorl, rendering spiral cords more finely and closely beaded; umbilicus lacking in all except small juveniles (<4 whorls), but often obscured by reflected columella even in these. Peristome markedly oblique, more or less in one tangential plane; aperture roundly D-shaped, flattened parietally; columella lip a thic kened pillar with 2 well developed teeth separated by a shallow concavity; lower tooth stronger and frequently squarish with a raised ridge along its lower margin, upper tooth weaker and clearly representing the end of a subparietal spiral pleat; pleat separated from paries by a U-shaped notch; umbilical region median to thickened columella pillar sunken, forming an elongate, more or less rectangular pit; pit bordered basally by a medial extension of ridge of lower columella tooth; umbilical/parietal region covered by inductural callus; callus translucent, smooth and glossy, raised somewhat basally and confluent with flaring margin of outer lip; interior of outer lip with a subterminal thickening corresponding in position with the external labral varix; thickening set with numerous elongate denticles and rounded tubercles, these not running into deeper por tions of aperture; 2-3 denticles closest to junction of basal and columella lips larger, forming a two-to three-humped bulge, which together with the lower columella tooth delineates a pronounced U-shaped notch; margin of outer lip flaring; interior of aperture nacreous, somewhat angled beneath spiral cords of shell exterior, but not spirally lirate. Microsculpture (Fig. 16B, C): First teleoconch whorl with vermiform spiral threads, replaced on subsequent whorls by prosocline, scratch-like microsculpture, filled with intritacalx deposit. Protoconch (Fig. 16A, C): Translucent white; diameter ca 360 μm; level with or slight ly sunken below first teleoconch whorl and somewhat down-tilted; degree of til ting variable between individuals; surface mostly worn, but with traces of irregular gra nula tion; terminal lip weakly sinuous.
Colour: Spire apex uniform white, later whorls (3 rd onwards) with pale fawn ground patterned with darker, brownish markings; markings initially in the form of axial bands or blotches, but penultimate and last adult whorls rather more randomly mottled; subter minal varix and flaring edge of outer lip with brownish spiral bands in cord in tervals; pre cise shade and density of colour pattern variable between individuals, some specimens very sparsely marked, but outer lip varix evidently patterned in all; cord in tervals with pink/green iridescence; living and fresh specimens with a buffish intrita calx deposit. Shell exterior of live-taken specimens often with some encrustation by other marine organisms, but not (in the material available) entirely covered with sponge.
Operculum (Fig. 4E): Initially tightly multispiral, but whorls broadening with growth and becoming more openly multispiral. developed transverse ridge, cutting edge coarsely dentate with elongate-lanceolate central denticle with narrowly acuminate tip, and up to 5 lateral denticles on each side, last of which forms a rounded boss at shoulder of tooth. Laterals with overlapping shafts and trigonal, distinctly asymmetrical cusps, decreasing in size from first to fourth; inner cut ting edge curved and finely serrate almost from tip, outer cutting edge nearly straight and set with coarse, close-set, more elongate denticles, starting some distance back from tip; first lateral strongly hunched at outer base of cusp. Marginals very long and slender, the cusp elongate, sides frequently in-rolled, and with a fringe of fine denticles on outer mar gin and at tip; outer shaft base of inner 1 or 2 marginals expanded and jaggedly ser rate; serrations continue sparsely up shaft.

Radula
External anatomy (Fig. 6C): Body whitish with some brownish pigmentation on sides of foot, lateral regions of snout and around base of cephalic tentacles. Cephalic lappets distinct, their free margin smooth or at most shallowly lobate (rather than digitate), its edge minutely papillate; lateral expansions of snout broad; right post-ocular peduncle present in both sexes, a longitudinal groove on its upper surface; right subocular tentacle not evident; right neck lobe with approx. 4 moderately large, first-order tentacles anteriorly; left neck lobe with a group of 8-10 slightly smaller first-order tentacles anteriorly, with even smaller intermediaries; left neck lobe with approx. 5 epipodial sense organs on under surface, right lobe with approx. 3; posterior part of both lobes smooth; epipodial fold with 7-9 tentacles of various sizes, but without very small intermediary tentacles; larger tentacles each with a distinct epipodial sense organ at the base. . Evidently a rather rare species, dead shells have been dredged in relatively deep water on rather lifeless muddy substrata (e.g. the Tugela Bank), but the five living specimens available were all collected in sponge communities on hard substrata near the continental shelf break. The absence of records from off central KwaZulu-Natal probably reflects less extensive dredging on the outer continental shelf and upper slope in this area. Remarks: Danilia textilis closely resembles D. discordata Vilvens & Héros, 2005 from Vanuatu, particularly in terms of the number and relative strength of the spiral cords. In both species there are eight spiral cords above (and including) the periphery (the ninth cord mentioned by Vilvens and Héros (2005) is subperipheral), of which the peripheral cord is somewhat larger and distinctly more spiniform than those above it. Both species also have a strong, squarish lower columella tooth and a colour pattern of brown, frequently axial, markings on a pale fawn ground. However, in D. discordata the six spiral cords between the subsutural and peripheral cords are wider and conspicuously flattened, as are the beads where the cords are crossed by the axial pliculae. In D. textilis the spiral cords are rounded and narrower than their intervals and retain raised rounded beads. The sculpture throughout is of a regular, open, oblique, net-like reticulation.
In this regard it resembles D. insperata Beu & Climo, 1974 from New Zealand, but that species has more evenly rounded whorls with fewer spiral cords (six above and in cluding periphery) and a less robust lower columella tooth. D. weberi Schepman, 1908 from Indonesia and the western Pacific has more numerous spiral cords due to intercalation of intermediaries, has beads that are angular rather than rounded and has a broader, more robust basal columella tooth. The recently described D. stratmanni Poppe, Tagaro & Dekker, 2006 from shallower water (-50-150 m) in the Philippines has much finer sculpture, more numerous spiral cords and lacks spiniform beads on the peripheral spiral cord. D. boucheti, the only other species of Danilia recorded from the south-western Indian Ocean, is considerably smaller and has an almost biangular whorl profile. The precise form of the apertural dentition varies considerably between individuals and is presumably related to maturity. There is evidently further thickening of the columella lip and its teeth, even after the subterminal varix and flared outer lip margin have formed.
Etymology: From Greek asketos (curiously wrought or ornamented) and stoma (a mouth); in reference to the complex apertural features. Gender neuter. Type species: Euchelus providentiae Melvill, 1909. Diagnosis: Whorls rounded, suture indented and somewhat channelled; sculpture of finely beaded spiral cords; umbilicus present, lined and apically plugged with callus; columella pillar with a well developed, squarish, basal tooth and a smaller, more rounded, upper one; parietal region with spreading, glossy, translucent callus deposit bearing short oblique ridges; callus deposit extending around umbilical margin and joining basal lip; umbilical margin with several small denticles and one larger one in parietal region; interior of outer lip subterminally thickened and bearing ridge-like denticles arranged more or less in 2 rows; base of columella with pronounced U-shaped notch between basal columella tooth and first outer lip denticle; exterior of outer lip also with a low, broad, subterminal thickening; suture descending at aperture when mature.
Remarks: Similar to the Herpetopoma group of species, but characterised by the callus lined umbilical depression, spirally ridged parietal callus and denticulate umbilical margin. Danilia also has a callus lined depression in the umbilical region, but in members of that genus it is shallower and trough-like; they also possess a strong, well-defined, rib-like external varix behind the outer lip. Clypeostoma has at most a faint umbilical depression and a much more extensive inductural callus deposit. In Ascetostoma the sculpture is also more finely and closely beaded than in Clypeostoma.

Description:
Shell: Trochoid-turbiniform, moderately elevated (L/D=1.04-1.26); teleoconch of 5.0-5.5 rounded whorls; suture indented and somewhat channelled, that between last adult whorl and penultimate whorl inserted at level of second subperipheral cord, but descending below this just prior to aperture; exterior of outer lip with a broad low subterminal thickening. First teleoconch whorl with approx. 20 axial pliculae; 3 spiral cords develop during second whorl (lowest level with abapical suture), and a fourth arising beneath adapical suture near end of whorl; subsequent whorls with further cords arising through intercalation; penultimate whorl with 7-9 cords, sometimes alternating a little in strength, sometimes not; seventh cord usually peripheral; cords well defined, equal to or wider than their intervals. Axial pliculae of first whorl persist on later whorls rendering spiral cords beaded where they cross them; beads of early whorls more or less rounded, but later becoming somewhat axially elongate, those on subsutural cord usually largest; axial pliculae well developed on spire whorls rendering sculpture cancellate, usually less prominent on last adult whorl. Base with 6-7 primary spiral cords and occasional intermediaries, sculptured as above. Peristome markedly oblique, more or less in one tangential plane; aperture subcircular to D-shaped, flattened parietally; columella lip protrudes into aperture as a thickened pillar which bears 2 well-developed teeth separated by a concavity; basal tooth often squarish, upper one somewhat smaller and more rounded; a deep U-shaped notch separates basal tooth from first denticle of basal lip; parietal region with glossy, translucent inductural callus, sculp tured with a variable number of ridges extending into aperture; ridges sometimes bi fid terminally; a well-developed parietal tooth projects from paries over umbilical depression; umbilicus present, lined and apically plugged with smooth, white callus when mature, conventionally patent in juveniles; umbilical margin thickened, also covered with callus and bearing ridge-like denticles (only in fully mature of specimens); callus slightly raised basally and confluent with flaring margin of outer lip; interior of outer lip with 2 rows of ridge-like denticles (at maximal maturity), the inner row stronger and lying on subterminal thickening of lip interior, the outer row (on non-nacreous flaring lip margin) weaker and less distinct; 2 denticles of inner row, nearest basal columella notch, usually larger; a small rounded or elongate granule may be present on columella near bottom of basal columella notch; interior of aperture nacreous, somewhat angled beneath spiral cords of shell exterior, but not spirally lirate.
Microsculpture (Fig. 19B, C): Early teleoconch whorls with fine vermiform spiral threads; microsculpture of subsequent whorls often completely obscured by encrusting organisms; little evidence of any superficial intritacalx deposit and scratch-like sculpture scarcely evident; microsculpture instead comprising irregular, somewhat oblique, vermiform threads, most noticeable on the spiral cords (Fig. 19B).
Colour: Most specimens uniformly rich orange-brown with darker spots on spiral cords of second and third whorls; occasional specimens with alternating darker and lighter blotches below suture; cord intervals faintly iridescent; umbilical region white; pigmentation of old, dead shells frequently rather more pinkish/purplish brown. Shell exterior of live-taken specimens usually more or less entirely covered with a thin, brownish or blackish, spiculiferous, encrusting sponge (Fig. 18E). Dimensions: Greatest length 9.0 mm, greatest diameter 8.0 mm, but size at maturity evidently variable; some specimens of length ca 7.0 mm possess mature apertural dentition. Operculum (Fig. 4F): Initially tightly multispiral, but whorls broadening with growth and becoming more openly multispiral. Radula (Fig. 19D, E): Formula ∞+4+1+4+∞; ca 75 transverse rows of teeth. Rachidian with trigonal cusp and well-developed hood; base of cusp with weak transverse ridge; cutting edge coarsely dentate, central denticle largest, lanceolate and with 3 or 4 smaller denticles on each side. Lateral tooth cusps with an elongate, rather spathulate central denticle and relatively coarse secondary denticles on outer margin, inner margin with few if any denticles. Inner marginals more slender with a recurved, dentate cusp, the denticles on outer margin extending some way down shaft; middle marginals very slender, but outermost ones shorter, broader and very delicate. External anatomy (Figs 5A, 6A): Head-foot with extensive dark brown to black pigmen tation in living animal; cephalic tentacles more or less uniformly dark; blackish colour of neck lobes and epipodial tentacles contrasting with whitish upper parts of foot. Cephalic lappets finely digitate, not meeting in mid-line; snout laterally expanded, Fig. 19. Ascetostoma providentiae (Melvill, 1909) transversely striped with black, lips split mid-ventrally; right post-ocular peduncle relatively small, arising from base of eyestalk; subocular tentacle not evident; right neck lobe with approx. 5 closely spaced tentacles anteriorly (increasing in size from first to last) followed by 2 or 3 more widely spaced ones; left neck lobe with numerous, closeset tentacles along most of its length, more or less similar in size; epipodial fold with approx. 10 tentacles of various sizes, the larger ones each with a basal epipodial sense organ; epipodial sense organs not evident beneath neck lobes, but some larger neck lobe tentacles with a pale basal spot that may represent such a structure.
Type material: Melvill (1909) stated that he had examined two specimens and selected the larger as the 'type' [holotype]. The second specimen would therefore be a paratype. Two specimens were originally registered under NHMUK 1910.3.17.2-3, but only one is now present. This is smaller than the dimensions given by Melvill and is presumably the paratype; length 6.6 mm, diameter 5.9 mm. It is a subadult specimen in which the apertural dentition is not fully developed (Fig. 18G, H Distribution and habitat (Fig. 20): Islands of the western Indian Ocean (southern Seychelles group and Mascarenes) and the Mozambique Channel south to north-eastern South Africa (28.3°S, off Mission Rocks); - 35-195 m (living specimens -50-85 m). In Zululand this species appears to inhabit hard substrata beyond the line of the near-shore reef system, where the sea floor is composed of fragmented sandstone or coral rubble, and is generally rich in marine life. Evidently a mid to outer continental shelf species throughout its range and not part of the shallow-water coral reef biota.
Remarks: This species is very similar to Euchelus ringens Schepman, 1908 from the Su lu Archipelago, Indonesia, and the two may eventually prove to be synonyms. The columella lip of the holotype of E. ringens (Fig. 68A, B) is somewhat damaged (perhaps due to occupation by a hermit crab) and looks rather deformed. Compared with southwestern Indian Ocean material it differs in being slightly less elevated and in having a narrower umbilicus; there are also minor differences in terms of coloration and aperture characters. In the absence of data on variation in Indonesian material, I have chosen, to err on the side of caution and maintain Ascetostoma providentiae as a distinct species. There can be no doubt, however, that E. ringens is also a species of Ascetostoma. A. providentiae is easily distinguished from the other southern African chilodontid taxa by its rounded whorl profile, very strong, complex apertural dentition and patent, callus lined umbilicus. 'Clanculus' crassilabrum Sowerby, 1905 (Fig. 68C, D) from Sri Lanka has a similar overall facies, but lacks the unusual umbilical features of Ascetostoma and is probably closer to Herpetopoma. Also similar is Herpetopoma rubrum (A. Adams, 1853), from Japan to SE Asia, which is likewise often vividly coloured, but in that species the inductural callus does not extend over the umbilical region and the umbilicus remains conventionally patent even at full apertural maturity. The Japanese Euchelus lischkei Pilsbry, 1904 also resembles A. providentiae in size, shape and sculpture, but has a much weaker basal columella tooth and has a simple, patent um bilicus. The Philippine material identified under this name (as Clanculus) by Kosuge and Chino (1998) is not in fact referable to this species.
The Cretaceous Chilodonta (Agathodonta) africana Rennie, 1930 from the Pondo land coast, Eastern Cape (holotype, SAMC 8630) is superficially similar to A. providentiae, but it has finer granules above the periphery, distinct prosocline pliculae below the suture and a smoother base. It has a well-developed tubercle on the basal lip separated from the columella by a U-shaped notch, but no details of its umbilicus are apparent. Species of Euchelus s.s. are generally larger shelled than those of Herpetopoma, have a single weak columella tooth and lack a deep U-shaped notch at the base of the co lumella. Evidently Euchelus s.s. is scarce in the south-western Indian Ocean. Only two species have been recorded from the region and I have seen no further material re ferable to this genus.
Euchelus alabastrum (Reeve, 1858)  There is no type material for this species in the NHMUK and although Reeve mentioned additional material in the Cuming collection, no specimens identified under this name could be found in the NHMUK general collection. Nonetheless, two spe cimens labelled 'triangulata var.' (without locality), from the Cuming collection, bear considerable resemblance to Reeve's original figure of Trochus alabastrum (Fig. 21A). The larger of the two is here figured for comparison (Fig. 21B). Like alabastrum it is chalky-white with small spots (now much faded and pale purple-brown rather than black) on the spiral keels.
This material represents pale, particularly strongly keeled individuals of the quadricarinatus form of the highly variable Euchelus asper (Gmelin, 1791). Although it can not be considered type material for T. alabastrum, its resemblance to the description and original figure of the latter strongly suggests that it may have been the Cumingian material referred to by Reeve. There can be little doubt that it is conspecific therewith. I therefore propose that Trochus alabastrum Reeve, 1958 be considered a synonym of Euchelus asper (Gmelin, 1791) and that it represents the form quadricarinatus (Holten, 1802) (cited figure reproduced in Fig. 21C) of that species. Monodonta tricarinata Lamarck, 1822 is already established as another synonym (Fischer 1878(Fischer in 1875. This form of the species is evidently widespread in the Indo-West Pacific, occurring as far east as Japan (Sasaki 2000). It was also recorded from Durban by Sowerby (1897), but it seems more probable that this was a misidentified or mislocalised specimen. Fresher material from Thailand is illustrated for comparison (Fig. 21D) and an additional figure was provided by Poppe and Tagaro (2008: pl. 43:8). The extent of variation within E. asper is considerable and requires further study in order to evaluate its significance and to determine if it is genetically, environmentally or sexually determined.
The original Trochus alabastrum material described by Reeve (1858) came from the collection of Sir David Barclay, which was sold at auction in 1891 (Dance 1986). Some types from this collection were subsequently purchased by the NHMUK from G.B. Sowerby (3 rd ), but the whereabouts of others is not known (J. Pickering pers. comm., Feb. 2011).
Euchelus atratus (Gmelin, 1791) Thiele (1917) and Drivas & Jay (1988) recorded this species from the Comoros and Réunion respectively. A single specimen is present in the Jay coll'n (MNHN), but it is  The type species of Herpetopoma, Euchelus scabriusculus Adams & Angas in Angas, 1867, from southern and south-eastern Australia, is a small gemmate species with a simple, open umbilicus bordered by a strongly beaded spiral cord. The columella is likewise relatively simple with a single well-developed tooth at its base. Another welldeveloped tooth is situated on the basal lip, close to its junction with the columella, the space between these teeth forming a deep U-shaped notch. The inner margin of the outer lip is set with numerous small, ridge-like denticles and the operculum is openly multispiral, with a broad growing margin (Fig. 4H).
Herpetopoma has frequently been treated as a subgenus of Euchelus, but like most more recent authors, I consider it to represent a distinct radiation and to be worthy of recognition at generic level. Species of Euchelus s.s. are generally larger and have an operculum with fewer, more rapidly expanding whorls (see above). Although they may have a single simple tooth/denticle at the base of the columella, they mostly lack the characteristic pattern of two teeth at the junction of the columella and basal lips, separated by a U-shaped notch, which is typical of Herpetopoma. Other taxa (e.g. Ascetostoma, Clypeostoma and Danilia) that exhibit this last feature have additional characters, which set them apart from Herpetopoma.
However, even when recognised as a genus itself, Herpetopoma, may prove to be a composite taxon, given the diversity of shell form evident in the species assigned to it. I have reasonable confidence that H. instrictum, H. seychellarum, H. serratocinctum and H. stictum are correctly placed in this genus and refer them to Herpetopoma sensu stricto. However, I am less certain about H. helix, H. ?naokoae and H. xeniolum and thus consider them Herpetopoma sensu lato. The protoconch is more exsert and evidently less strongly sculptured, the juvenile microsculpture sometimes granular rather than vermiform and, at least in H. helix, the operculum is tightly multispiral throughout.
No well preserved alcohol material is available for any of the local species of Herpetopoma and thus details of the external anatomy are not available. However, I have been able to extract a radula from H. helix as well as from dried specimens of the type species loaned from the Australian Museum, Sydney. Details of the latter are given below.
Radula (Fig. 22): Formula ∞+(3-4)+1+(3-4)+∞; ca 55 transverse rows of teeth; transition from lateral to marginal series relatively clear. Rachidian with broad, tri gonal cusp and well-developed hood; cusp with strong transverse ridge at its base, this ge nerally concave due to medial indentation near cusp base; cutting edge coarsely den tate, central denticle largest, lanceolate, with 2-4 smaller denticles on each side. Lateral teeth progressively decreasing in size from first to last, but not markedly so; one specimen with 3 pairs of laterals per row, another with four; cusp elongate-trigonal to spathulate, bearing coarse lateral denticles on both margins (3-6). Marginals longer and more slender than laterals, but relatively shorter than in other genera; inner marginals distinctive in having a slender, recurved cusp with a few short, barb-like denticles near the tip on inner margin and a series of much longer, close-set, curved denticles on outer margin, the central part of the cusp appearing as a rib-like structure from which the two series of denticles project (Fig. 22C); remaining marginals with smaller, ladle-shaped cusps with a finely pectinate margin, the outermost one with a somewhat enlarged cusp (Fig. 22D). Key to species of Herpetopoma in the south-western Indian Ocean 1 Basal columella tooth a well-developed peg with a deep U-shaped notch separating it from the first (usually the largest) tooth inside the basal lip (Fig. 23) ................2 -Basal columella tooth smaller and roundly trigonal; U-shaped notch at base of columella relatively shallow (Fig. 32)

Description:
Shell: Trochoid-turbiniform, moderately elevated (L/D=1.10-1.25); teleoconch of up to 6.5 whorls; spire whorls somewhat flat-sided; suture strongly indented, inserted at level of subperipheral cord and thus appearing somewhat channelled, descending slightly just prior to outer lip. First teleoconch whorls sculptured with curved axial pliculae; 2-3 spiral cords arise during second whorl, and additional ones with subsequent growth; penultimate whorl with approx. 5 well developed cords, a sixth level with suture; subsutural cord strongest, but becoming distinctly weaker just behind outer lip; cords equal to or narrower than their intervals. Axial pliculae of first whorl persist on later whorls producing a distinct cancellation and rendering spiral cords granular where they cross them; granules of subsutural cord usually largest, becoming smaller and more numerous toward periphery; interstices more or less square on spire whorls, becoming axially elongate on last adult whorl, particularly so just behind outer lip. Base similarly sculptured with approx. 6 spiral cords, the last of which forms umbilical margin; umbilicus remaining open at maturity (very occasionally almost occluded by reflected columella). Peristome oblique; aperture D-shaped, flattened parietally; columella thickened, bearing a low bulge in the mid region and a well-developed, peg-like tooth basally; a deep U-shaped notch separates basal columella tooth from first denticle of basal lip; parietal callus not extending far beyond aperture, bearing spiral ridges; mar gin of outer lip somewhat flaring, the edge finely and rather irregularly crenulate; interior of outer lip with a subterminal thickening which is set with relatively strong, in-running, ridge-like denticles, these become weaker toward lip margin and develop finer intermediaries (at maximal maturity); denticles not extending far into aperture, one nearest basal columella notch usually larger; 1 or 2 small rounded granules may be present on columella near bottom of basal columella notch; interior of aperture nacreous; exterior of outer lip some times with a broad low subterminal thickening, but lacking a rib-like varix. Microsculpture ( Fig. 24A-C): Juvenile shell with vermiform spiral threads; later whorls with close-set, scratch-like marks beneath intritacalx. Protoconch (Fig. 24A, C): White, more or less level with first teleoconch whorl or at most weakly exsert, with a weak apical beak; diameter 220-240 μm; terminal lip distinctly convex; superficial sculpture well developed, arranged in irregular axial lines, with a weak spiral element.
Colour: White to yellowish white, later whorls with reddish to brown spots, blotches or axial flames; markings generally browner in fresh specimens; a white to dirty brown intritacalx is present in fresh specimens but this is worn off in most museum material. Shell surface often encrusted by other marine organisms.
Operculum (Fig. 4G): Initially tightly multispiral, but whorls broadening with growth and becoming more openly multispiral. Radula and external anatomy: Unknown except for some brief comments on the external anatomy made by A. Adams (1864b). A figure of a living specimen was also provided by Sasaki (2000: 56).
Type material: Holotype of Trochus instrictus Gould, 1849, in USNM (5625) (Fig. 23A, B see also Kaicher 1990), length 8.3 mm, diameter 7.5 mm (measured from photograph scale, dimensions given by Gould equate to 9.5×7.6 mm); four syntypes of Monodonta alveolata A. Adams, 1853 in NHMUK (196872), the best of which is here figured and designated lectotype, length 11.9 mm, diameter 10.0 mm (Fig. 23E, F); holotype of Monodonta bourcierei Crosse, 1863 in NHMUK (96.12.1.13), length 8.6 mm, diameter 7.0 mm (Fig. 23G, H). Distribution and habitat (Fig. 25): Indo-West Pacific; from southern Japan, SE Asia and the south-western Pacific to western Australia, the Andaman Islands and East Africa; in the western Indian Ocean extending south to southern Madagascar, but not yet recorded from central or southern Mozambique, or South Africa. Recorded from Quaternary deposits in the Marshall Islands (Ladd 1966). Little information regarding the habitat of living animals is available. Adams (1864b) reported a living specimen dredged at 55 fath.
[-100 m] off southern Japan, but most of the specimens available (live and dead collected) have come from near-shore reef systems with a coralline facies (AMS and WAM material). Wilson (1993) gave the bathymetric distribution as intertidal to -140 m, but did not specify whether this concerned living or dead material. Sasaki (2000) (Fig. 29), however, are much less elevated, whilst H. gemmatum and H. crassilabrum (Fig. 68C, D) have more rounded whorls with relatively close-set and more obviously beaded spiral sculpture, the latter also has a more strongly developed upper columella denticle and a partially occluded umbilicus; all are smaller than H. instrictum. Amongst south-western Indian Ocean chilodontid taxa, only H. seychellarum retains a simple and deep umbilicus when mature, but that species is considerably smaller and more depressed.

Figs 26-28
Etymology: From Latin serratus (toothed like a saw) and cinctum (a belt or girdle); in reference to the strong, toothed peripheral cord. Description: Shell: Small, turbiniform, relatively solid; length more or less equal to diameter (L/D= 0.97-1.1); teleoconch of approx. 3.5 whorls; whorls rounded at periphery, but with a strong peripheral spiral cord; suture indented, level with subperipheral cord, but descending below this immediately prior to aperture in mature individuals; first teleoconch whorl initially sculptured with strong, widely spaced, curved, axial pliculae; pliculae becoming thinner and more close-set after one quarter whorl; 2 spiral cords arising in latter half of whorl; both axial and spiral sculpture strengthening during second whorl and a third spiral cord arising beneath adapical suture; axial pliculae prosocline, more close-set than spiral cords creating obliquely rectangular interstices; cords with rounded nodules where crossed by axial pliculae; 2 further spiral cords arise by intercalation during third whorl, end of penultimate whorl thus with 5 spiral cords of alternating strength above suture; interstices more nearly square; beads on peripheral cord, well developed, stronger, more angular and fewer in number than on other cords (approx. 25 on last adult whorl), but those in final quarter whorl smaller, less angular and more close-set. Base with 4 primary spiral cords, a weaker fifth beneath peripheral cord and a sixth mostly hidden by reflected columella; beads of basal spiral cords progressively lower and more rounded toward umbilicus. Umbilicus closed in adults, but remaining open and steep-sided in juveniles, its edge marked by the sixth basal spiral cord. Peristome markedly oblique, almost tangential; aperture subcircular to D-shaped, flattened parietally; columella pillar well developed, protruding slightly into aperture, a strong, peg-like tooth at its base and a low bulge above its mid region; interior of outer lip subterminally thickened and set with 8-10 elongate denticles which extend into aperture as in-running ridges; that nearest columella larger, a deep U-shaped notch separating it from basal columella tooth; outer portion of lip flaring and bearing additional secondary granules and wrinkles distal to primary denticles; these continue around reflected portion of columella lip; parietal region covered with glossy callus bearing superficial wrinkle-like ridges; callus not extending beyond limit of peristome; interior of aperture nacreous. Microsculpture (Fig. 27B, C): Juvenile shell with vermiform spiral threads, these con tinue throughout shell, becoming oblique on last adult whorl (cf. Ascetostoma providentiae); the scratch-like adult microsculpture of other species is not evident. Protoconch (Fig. 27A, C): Greyish white, more or less level with first teleoconch whorl or at most weakly exsert; diameter ca 270 μm; terminal lip distinct, shallowly convex; superficial sculpture well developed, irregular and wavy, with a predominant axial alignment; no spiral component evident.
Colour: Fresh specimens translucent white with regular reddish spotting, mostly on the spiral cords and usually in more or less axially aligned rows; final portion of last adult whorl washed with pale orange-brown; some evidence of a dirty white intritacalx deposit remaining in sculptural interstices of fresh specimens.
Operculum, radula and external anatomy: Unknown. Distribution and habitat (Fig. 28): Known only from the coast of central Kenya and northern Mozambique, evidently in shallow subtidal habitats associated with fringing reef systems. Remarks: Amongst the regional fauna, H. serratocinctum most closely resembles the Mascarene H. stictum (see below), particularly in terms of size, coloration and apertural dentition. The less elevated spire, more angular sculpture and strong, saw-toothed peripheral cord of H. serratocinctum, however, are distinctive. There is also some similarity with H. fimbriatum (Pease, 1861) (Fig. 69C, D), reportedly from Hawaii (but see Kay 1979), and H. corallinum Jansen, 1994 from the Great Barrier Reef, but in both these species the columella has a weaker basal tooth and lacks a low bulge above this.   Remarks: This species does not appear to have been recorded subsequent to the original description. Its small size (diameter 2.8 mm), depressed profile and wide umbilicus, together with the distinct, peg-like basal columella tooth and dentate interior of the outer lip render it easily separable from other south-western Indian Ocean chilodontids. Obviously such small species are easily overlooked, but the evident absence of additional material from the Seychelles raises the possibility that the original material was mislocalised. Comparison with taxa from other areas may shed further light on this subject. The Philippine H. exasperatum (A. Adams, 1853) has a similarly depressed shape, but is larger (diameter attaining 6.5 mm) and has spiral cords of alternating size and crisper sculpture (Fig. 68E, F).

Etymology: From
Greek stiktos (spotted); in reference to the colour pattern.

Description:
Shell: Small, trochoid-turbiniform, relatively solid; length slightly exceeding diameter (L/D=1.07-1.19); teleoconch of approx. 4.5 whorls; spire whorls rather flat-sided, last adult whorl rounded, but slightly flatter below periphery; suture indented, level with sub peripheral spiral cord, but descending below this immediately prior to aperture in fully mature individuals; first teleoconch whorl initially sculptured only with axial pliculae (ca 20); 2 spiral cords arising in latter half of whorl, a third arising beneath adapical suture during second whorl, a fourth arising below subsutural cord during third whorl; end of penultimate whorl with 4 spiral cords of more or less equal strength above abapical suture; cords equal to or slightly narrower than their intervals and crossed by prosocline axial pliculae; pliculae slightly narrower than spiral cords, the latter with roundly angular beads where crossed by pliculae, those on subsutural and peripheral cords slightly stronger (ca 30 on peripheral cord of last adult whorl); interstices roundly quadrate. Base with 5 spiral cords, the outer (subperipheral) one strongest and with roundly angular beads, the others progressively with lower, more rounded beads; a weak sixth cord bordering umbilicus; cords slightly wider than their intervals. Umbilicus open in juveniles and subadults, steep-sided, occasionally remaining narrowly patent even at maturity, but generally occluded by reflected columella lip and if evident at all then only as a shallow depression. Peristome markedly oblique, almost tangential; aperture D-shaped, somewhat flattened parietally; columella pillar well developed, a little oblique and protruding slightly into aperture; a distinct, peg-like tooth at its base with a second low bulge sometimes evident above this; interior of outer lip thickened and set with 7 or 8 primary denticles which extend into aperture as in-running ridges; that nearest columella larger, a deep U-shaped notch separating it from basal columella tooth; outer portion of lip flaring and bearing additional secondary granules and wrinkles external to primary denticles; these continue around reflected portion of columella lip, one particularly strong secondary granule near base of basal columella notch; parietal callus not extending beyond limit of peristome, sometimes with traces of superficial wrinkle-like ridges; interior of aperture nacreous. Microsculpture (Fig. 31B, C): Apical whorls with vermiform spiral threads; weak scratch-like sculpture developing subsequently, but retaining traces of vermiform threads on spiral cords; interstices with sparse microscopic granules. Protoconch (Fig. 31A, C): Translucent whitish in fresh specimens, last quarter whorl and initial half of first teleoconch whorl mauve-brown; more or less level with early part of first teleoconch whorl, its apex slightly down-tilted; diameter 250-280 μm; terminal lip weakly convex; superficial sculpture well developed, irregular and wavy, with a predominant axial alignment; no spiral component evident.
Colour: Whitish with sparse, mauve-brown spots on spiral cords; spots sometimes aligned into diffuse axial bands on last adult whorl; base with fewer spots, generally more uniform white; spots fading to pinkish brown in old or worn specimens; fresh examples with a thin, dirty-buff, chalky intritacalx deposit.
Operculum, radula and external anatomy: Unknown.   Jansen, 1994 from Lord Howe Is. is also spotted, but has a less elevated spire, a weaker basal columella tooth and has intermediary spiral threads between the primary spiral cords. The Hawaiian H. corrugatum (Pease, 1861) has a more roundly beaded sculpture, a weaker basal columella tooth, a less obviously spotted colour pattern and commonly retains an open umbilicus (Fig. 69A, B). H. fimbriatum (Pease, 1861), also reportedly from Hawaii, has a more angular periphery and only three spiral cords on the penultimate whorl, and lacks a spotted colour pattern (Fig. 69C, D). Jay (2009) confused the present species with another Pacific species, H. gemmatum (Gould, 1845), but that species has more rounded whorls, a more finely beaded sculpture and a clearly patent umbilicus. (NB: The shell figured by Johnson (1964: pl. 15, fig. 10) as the lectotype of Trochus (Monodonta) gemmatus Gould, 1845, with a diameter of 20 mm cannot in fact be the genuine lectotype.) Diloma verruca Gould, 1861, a very poorly documented species from Chinese waters, also belongs within this group of Herpetopoma species, but has two widely spaced primary spiral cords at and just above the periphery of the last adult whorl (Fig. 69E, F).

Description:
Shell: Turbiniform (L/D=1.10-1.25), teleoconch of 4-5 whorls; whorls rounded, sutures indented and inserted at level of subperipheral cord; first teleoconch whorl with 14-16 axial pliculae; second and subsequent whorls with axial pliculae and relatively strong spiral cords, 2 on second whorl, 3 on subsequent ones; cords bearing axially elongate beads where crossed by pliculae; last adult whorl with 40-50 axial pliculae and 3 spiral cords above and including periphery, occasional specimens with weaker intermediaries; intervals between cords equal to or wider than cords themselves and rendered obliquely cancellate by axial pliculae; interval between second and third cords frequently wider than others. Base with 4-5 somewhat less well developed spiral cords, sometimes with a sixth close to columella; axial pliculae of base progressively less elevated toward shell axis and cords thus less obviously granular. Umbilicus lacking in adult specimens, but sometimes evident as a narrow chink in juveniles; umbilical region usually at least partially covered by parietal/columella callus. Peristome oblique; aperture subcircular, flattened at paries; columella with a single simple tooth at its base; interior of outer lip thickened, bearing approx. 12 ridge-like denticles, one where basal portion of lip joins columella frequently larger, with a shallow notch separating it from columella tooth; an additional small granule is usually present just external to this notch; exterior of outer lip thickened subterminally but not distinctly varixed; interior nacreous, deeper region lacking in-running ridges, but cords of outer surface showing through. Microsculpture ( Fig. 33A-C): Vermiform spiral threads not evident on apical whorls; microsculpture between axial pliculae instead comprising numerous crisp granules, frequently connected by thread-like axial elements; adult microsculpture similar but rather more irregular and often completely obscured by thick intritacalx deposit. Protoconch (Fig. 33C): Translucent white; diameter 260-280 μm; moderately exsert and relatively globose; worn in all available material; terminal lip shallowly convex; superficial sculpture mostly eroded, but with traces of granulation remaining near suture.
Colour: Shell evidently more or less uniformly greyish white to yellowish white and somewhat translucent; intritacalx deposit usually yellowish white to buff-brown, but some specimens patterned with broad bands in shades of brownish grey.
Operculum (Fig. 4I): Relatively tightly multispiral throughout. Radula (Fig. 33D, E): Formula ∞+4+1+4+∞; ca 40 transverse rows of teeth; transition from lateral to marginal series not well defined, the fourth lateral could also be interpreted as a marginal. Rachidian with broad, trigonal cusp and well-developed hood, but lacking a distinct transverse basal ridge and near-basal medial indentation; cutting edge with a very long, acuminate, central denticle and 2 or 3 smaller, likewise elongate denticles on each side. Lateral teeth progressively decreasing in size from first to last, but not markedly so, their cusps obliquely trigonal with coarse lateral denticles on both margins (3-5). Marginals closely resembling those of H. scabriusculum, but a little more elongate; cusps of inner marginals with well-developed pectinate outer margin; outermost marginals shorter and with a somewhat dilated, fringed cusp.
External anatomy: Evidently chilodontid, but material insufficiently well preserved to provide meaningful detail.  -193-194 m, 9.iv.2009    characteristic dirty buff and grey intritacalx deposit typical of many chilodontids. All others are uniform off-white. The protoconch is translucent white, globose and exsert, with a diameter of ca 285 μm; in the material available the surface is worn and sculptural detail not evident. The apical whorls of the teleoconch have a microsculpture of vermiform spiral threads that become more oblique and fragmented with growth, the adult microsculpture comprising a fine, irregular granulation. Herpetopoma pruinosum (Marshall, 1979), from the Kermadec Ridge, is also similar but has a lower spire and a finer, more obviously cancellate sculpture. Additional similar, but more elongate specimens have been sorted from some of the same dredge samples collected off Réunion and are discussed below (see H. xeniolum).
Herpetopoma (s.l.) xeniolum (Melvill, 1918) Melvill, 1918in NHMUK (1921Trew (1987) was in error in stating that there were three specimens registered. Holotype of Turcica (Perrinia) waiwailevensis Ladd, 1982 in USNM (2501420). Holotype of Herpetopoma eboreum Vilvens & Héros, 2003  Remarks: A number of samples collected off Réunion are evidently referable this species, which I consider is closer to Herpetopoma than to Euchelus on account of its small size and the U-shaped notch at the columella base (albeit relatively weak). The species is poorly known and has not to my knowledge been recorded subsequent to the original description. The holotype (Fig. 37A, B) has four granular spiral cords on the penultimate whorl as do some Réunion specimens (Fig. 37C, D). However, other specimens in the Réunion samples have five such cords (Fig. 37E, F) and closely resemble the holotype of Turcica (Perrinia) waiwailevensis Ladd, 1982 from the Pliocene of Fiji (Fig. 37G,  H). I have no doubt that the Réunion samples belong to a single species and consider the number of spiral cords on the penultimate whorl (four or five) to be a variable character. There is evidently similar variation in the number of spiral cords on the base (6-8  Moolenbeek & Faber, 1989 from the Caribbean is another similar species, but is evidently smaller (length up to 3.2 mm) and has somewhat coarser sculpture. The holotype of H. xeniolum was collected in shallow water (-9 m) and similarly the overall facies of the fauna at the type locality of H. waiwailevensis is that of a shallowwater, lagoonal system (Ladd 1966(Ladd , 1982. The depth at which the dredged material from Réunion was obtained (-110-340 m) would thus seem to be anomalous. However, Réunion has a steeply shelving sublittoral zone and dead specimens of typically shallowwater species are frequently found at greater depths. That the species is also present in the M. Jay collection (MNHN) suggests that it does indeed occur in relatively shallow water around Réunion. The same may also apply to some rather worn specimens from off the steeply shelving coast of Nosy Be, which I also tentatively identify as H. xeniolum.
This material resembles H. ?naokoae (above), but the whorls are less convex and the shell is consistently more elevated, L/D usually >1.23, spire height/aperture height usually >1.60 in H. xeniolum (usually <1.23 and <1.60 respectively in H. ?naokoae). Additionally, in H. ?naokoae the sculpture is coarser and the denticles inside the outer lip, although ridge-like, are restricted to the thickened region just inside the lip edge. In H. xeniolum some of these ridges extend deeply into the aperture. Furthermore, in the local H. ?naokoae specimens there is an additional small denticle adjacent to the notch between the two larger denticles at the junction of the base and columella, this is not present in the H. xeniolum material examined.
The protoconch is translucent white with a diameter of ca 220 μm; its surface is eroded in the material available. A microsculpture of irregular vermiform spiral threads is present on the early teleoconch whorls; subsequent whorls with weak oblique vermiform threads and traces of very fine scratch-like marks.
Genus Vaceuchelus Iredale, 1929Vaceuchelus: Iredale 1929 The shell of Vaceuchelus species is small (length <10 mm), predominantly white and has a cancellate or foveolate sculpture. The aperture lacks a well-developed, peg-like tooth and U-shaped notch at the base of the columella, and may or may not possess denticles inside the outer lip. Iredale (1929) proposed the genus for Euchelus angulatus Pease, 1868 from the Tuamotu Archipelago, noting that it typified a large series of taxa which differed from more typical Euchelus-like species primarily in lacking a tooth at the base of the columella. It is certainly true that Vaceuchelus species lack the distinctive basal columella dentition of some chilodontid genera, but a number of species still retain some form of apertural dentition. Two subgroupings are evident, namely those which possess denticles inside the outer lip and those that do not. The type species, together with V. foveolatus (A. Adams, 1853), V. scrobiculatus (Souverbie in Souverbie & Montrouzier, 1866) and V. semilugubris (Deshayes, 1863) possess labral denticles, whilst others, e.g. V. cavernosus (Sowerby, 1905), V. clathratus (A. Adams, 1853), V. favosus (Melvill & Standen, 1896), V. gemmula (Turton, 1932), V. jayorum sp. n. and V. natalensis (Smith, 1906), seem to lack all traces of apertural dentition.
To provide a new genus-rank name for such denticle-less taxa would be premature at this stage, since the distinction is based on one character only and, furthermore, there are additional taxa, e.g. V. cretaceus (see below), which present a third, somewhat intermediate facies. Until such time as the data set available allows a more meaningful assessment, I employ Vaceuchelus in its widest sense. Differences in operculum form and protoconch morphology, such as the presence or absence of a sinusigera lip, are also evident, but information is available for too few taxa.
V. angulatus is almost certainly a junior synonym of V. foveolatus (A. Adams, 1853), also from the Tuamotu Archipelago (Pilsbry 1890(Pilsbry in 1889. The holotype of the for mer is somewhat worn, but appears to be nothing more than an elevated and perhaps ab normal example of V. foveolatus in which the upper spiral cord is weakly developed (compare figs 72-73 and 74-75 in Herbert 1996).
Key to species of Vaceuchelus in the south-western Indian Ocean

Etymology: From
Greek creta (white earth or chalk); in reference to the superficial chalk-like intritacalx deposit on the shell.

Description:
Shell: Small, but relatively large for genus; elevated-turbiniform (L/D=1.0-1.25); teleoconch of 4.5-5.0 whorls; sculpture initially strongly cancellate, becoming foveolate with growth; spire truncate and protoconch sunken; first teleoconch whorl initially sculp tured only by rib-like axial pliculae, but 3 spiral cords develop soon thereafter, one forming shoulder, another level with the abapical suture and the third between these at whorl periphery; cords and pliculae thickening considerably during third whorl and becoming less well defined; intermediary cords absent, with the exception of a fourth cord which usually develops on shoulder during third teleoconch whorl; intervals between cords wider than cords themselves; cords and pliculae interact to produce low conical granules where they cross; last adult whorl with 15-20 pliculae, those behind outer lip usually poorly defined or obsolete; pliculae narrower than cords on early whorls, more or less equal to them on last adult whorl; interstices distinctly quadrate apically, but becoming more rounded and pit-like (foveolate) on last adult whorl; strong growth flaws frequently present on last adult whorl. Base with 3 spiral cords, one level with su ture, one marking edge of umbilicus and another between these; interval between outer and middle cords usually broader and with only weakly developed pits, that between middle and inner cords narrower and more strongly pitted; an additional cord is evident within umbilicus of young juveniles, but this becomes obscured with growth; umbilicus usually narrowly patent even in adults, occasionally closed; relatively wider in juveniles. Peristome oblique; aperture subcircular; columella concave with a broad rounded swelling at its base; swelling non-nacreous and rather variable in size; interior of aperture nacreous when fresh, lacking ridges or denticles inside outer lip. Microsculpture (Fig. 40B, C): Rather poorly defined and mostly covered by intritacalx deposit in fresh specimens; surface of apical whorls appearing etched, but with some traces of vermiform spiral threads; later whorls with close-set, shallow, prosocline, scratch-like marks.
Protoconch (Fig. 40C): White; diameter ca 200 μm; sunken; apex very slightly pinched in; terminal lip with a well-developed trigonal projection; superficial sculpture well developed, arranged in irregular axial lines, spiral element scarcely evident.
Operculum (Fig. 4J): Initially tightly multispiral, but whorls broadening with growth and becoming more openly multispiral. Radula (Fig. 40 D, E): Formula ∞+3+1+3+∞; ca 45 transverse rows of teeth; transition from lateral to marginal series not well delineated. Rachidian with well-developed hood and narrowly trigonal cusp; cusp with small medial indentation near its base; cutting edge with a dominant, lanceolate central denticle, with 2 or 3 smaller denticles on each side. Only 3 lateral teeth evident, the fourth tooth is longer and lacks the robust, alate shaft of the laterals, and I consider it to be a marginal; lateral tooth cusps decreasing slightly in size from first to third, with a large, spathulate central element and smaller lateral denticles on both margins, those on the outer edge coarser. Marginals generally long and very slender, tending to collapse when air dried; inner ones somewhat shorter with a rather weakly and irregularly dentate, recurved cusp, and lacking well-developed pectinate denticles on its outer margin.
External anatomy (Fig. 6F): Head-foot largely white, cephalic and most epipodial tentacles blackish; some additional dark pigmentation on snout and lips, and on free margin of cephalic lappets (colour lost in alcohol). Cephalic lappets relatively broad, but not meeting in mid-line, free margin with fine projections; snout with well-developed lateral flanges; right post-ocular peduncle present; right subocular tentacle not evident; free margin of left neck lobe more extensively tentaculate than that of right one; approx. 10 epipodial tentacles of varying size on each side; an indistinct epipodial sense organ seemingly present at base of most epipodial tentacles. (Only one preserved specimen available; paratype, NMSA S4006/T2638.) Holotype ( Fig. 39A-C Distribution and habitat (Fig. 41): South-western Indian Ocean, known only from Réun ion, southern Mozambique and northern Zululand (south to Mission Rocks); shal low subtidal to -250 m, but mostly shallower than -160 m (living specimens -50-70 m); dead shells not uncommon amongst lithothamnion encrusted pebbles and coral rubble in -50-70 m, beyond the near-shore reef system in northern Zululand.
Remarks: There is no similar species yet reported from the south-western Indian Ocean. V. gemmula, V. jayorum and V. natalensis are much smaller and thinner shelled, lack a basal columella swelling and retain sharply defined spirals and axials throughout. Although they may resemble juvenile V. cretaceus, they have a narrower umbilicus, more evenly spaced cords on the base and a less strongly truncated apex. Furthermore, in these small species the spiral cords are stronger in relation to the axial pliculae and more elevated than they are in V. cretaceus. V. semilugubris is also smaller than V. cretaceus, has denticles inside the outer lip when fully mature and is typically patterned with bold black markings. This species differs from V. angulatus (Pease, 1868) (type species of Vaceuchelus) and similar species from the south-western Pacific, such as V. foveolatus (A. Adams, 1853) and V. scrobiculatus (Souverbie in Souverbie & Montrouzier, 1866), in being larger and in lacking denticles or ridges inside the outer lip (cf. figures provided by Herbert 1996). More similar to V. cretaceus are V. cavernosus (Sowerby, 1905) from Sri Lanka (Fig. 70A, B) and V. clathratus (A. Adams, 1853) from the Philippines (Fig.  70C, D), both of which are of similar size and also lack sculpture inside the outer lip. Nonetheless, they retain a well defined, relatively fine, cancellate sculpture on the last adult whorl and have four and five spiral cords respectively on the base (including that level with suture) as opposed to three in V. cretaceus. Neither possesses the basal co lumella swelling of V. cretaceus. The most similar species is the recently described Vaceuchelus pagoboorum Poppe, Tagaro & Dekker, 2006 from the Philippines. This is clearly closely related to V. cretaceus and likewise possesses a broad swelling at the base of the columella, but differs in having an additional low rounded tubercle inside the outer lip near its junction with the parietal portion of the aperture, has more evenly spaced basal cords (four in juveniles compared with three in V. cretaceus, but the inner one becomes obsolete in adults), retains distinct pits in the interval between the outer and middle basal cords, and frequently has brownish markings on the spiral cords. With no material from intermediate localities, it is difficult to assess the significance of these differences, but they seem to constitute characters by which the populations can be distinguished and I thus describe the south-western Indian Ocean material as a new species. I refer this species to Vaceuchelus with some hesitation. The overall facies of its shell also shows some resemblance to that of Trochus clathratus Aradas, 1847, type species of Putzeysia Sulliotti, 1889. In that genus, however, the apex is not flattened, and the protoconch is globose and less strongly sculptured (Engl & Rolán 2009). The protoconch of V. cretaceus is closer to that of V. natalensis and V. gemmula, but differs in having a distinct projection on the terminal lip. Furthermore, whereas the radula of V. natalensis appears to be simply a reduced version of the Herpetopoma radula, that of V. cretaceus differs in having a narrower, acutely trigonal rachidian cusp and inner marginals that lack a strongly pectinate outer margin. With no comparable information available concerning the type species of Vaceuchelus, these differences are difficult to evaluate, but they suggest a degree of intrageneric variability within Vaceuchelus that merits further study.
Etymology: The species name gemmula, diminutive of Latin gemma (a bud or jewel) was formed as a feminine noun in apposition. Description: Shell: Small, turbiniform (L/D=0.90-1.15); teleoconch of up to 3.5 whorls; sculpture strongly cancellate; first whorl initially sculptured only with widely spaced, rib-like, axial pliculae (ca 15), but 3 spiral cords develop soon thereafter, one forming shoulder, another level with the abapical suture and the third between these at whorl periphery; cords persist and become progressively stronger with growth; an additional (fourth) subsutural cord may or may not develop on the shoulder during the last or penultimate whorl; no intermediary spiral cords; intervals between cords wider than cords themselves; last adult whorl with 20-30 axial pliculae; pliculae narrower than cords and somewhat lamellate, sometimes raised into squamose nodules where they cross cords; interstices obliquely quadrate. Base with 3 spiral cords, including that level with suture, usually with a weaker, rather ill-defined, fourth one present adjacent to columella; umbilicus closed or at most chink-like in adult, more obviously patent in some juveniles. Peristome Fig. 42. Vaceuchelus gemmula (Turton, 1932): (A) lectotype of Euchelus gemmula Turton, 1932, diameter 3.7 mm (OXUM); (B, C) live collected specimen, off Kwelera River, East London, South Africa, diameter 3.8 mm (NMSA S6100). oblique, aperture subcircular; columella concave, lacking dentition; outer lip notched at ends of spiral cords in juveniles and subadults, but less so in the largest specimens, when growth has ceased; even in the most mature specimens the outer lip is not conspicuously thickened and there is no trace of apertural teeth; interior nacreous and smooth, save for weak angles beneath external cords. Microsculpture (Fig. 43B, C): Vermiform spiral threads not evident on early whorls; later whorls with a granular microsculpture on the spiral ribs and sparse scratch-like marks in the sculptural interstices.
Protoconch (Fig. 43A, C): White, a little exsert and slightly down-tilted; diameter ca 340 μm; terminal lip very weakly convex; superficial sculpture well developed, arranged in irregular axial lines, spiral element weakly evident in some specimens.
Colour: White to pale greyish white, living specimens with dirty buff intritacalx deposit, particularly in sculptural interstices. Most material worn.

Radula: Unknown.
External anatomy: Uniformly white and evidently chilodontid, but preservation of material inadequate to establish anatomical details.
Type material: The type lot at OXUM contains three specimens, one, the largest, is marked with an X in the aperture. It is here figured and designated lectotype (Fig. 42A). This is probably the originally figured specimen, but it is difficult to be certain since the original illustration was heavily retouched.   Distribution and habitat (Fig. 44): Eastern Cape, South Africa; from the border with KwaZulu-Natal, south and west to the Port Elizabeth area; empty shells from beach drift to -500 m; living intertidally (under rocks), or subtidally on firm substrata to -115 m. A single isolated record from 400 km further to the west at Still Bay (Western Cape) requires confirmation.
Remarks: This species closely resembles Vaceuchelus natalensis and was in fact treated as a synonym thereof by Barnard (1963). There are, nonetheless, clear and consistent differences evident in adult individuals which indicate that two distinct taxa are involved. The most obvious of these are the larger protoconch, closed umbilicus and presence of only three major cords on the base in V. gemmula. In addition, the spiral cords of V. natalensis remain strong at the aperture margin, producing strong notches in the outer lip even in the largest individuals. Juvenile stages can be difficult to separate since the umbilicus of V. gemmula sometimes only closes in the later stages of growth. Turton (1932) observed that the axial pliculae were more numerous in V. gemmula (about 30 on last adult whorl) than in V. natalensis (ca 20). I cannot confirm this observation and find considerable overlap between the taxa in terms of the number of axial pliculae, as well as considerable intraspecific variation. The three specimens in the OXUM type lot have 20, 22 and 24 pliculae on the last adult whorl, the latter figure being that of the lectotype. V. gemmula evidently attains a somewhat larger size than V. natalensis. Little material of this species is available and most is in poor condition; only one live-collected adult specimen was to hand. The largest examples were obtained from beach-drift, but these are generally badly worn. Specimens from deeper water, off-shore habitats tend to be somewhat smaller, evincing an adult labrum at diameter ca 3.0 mm, and as in V. natalensis (below) they exhibit stronger nodules where the axial pliculae cross the spiral cords. The larger, less nodular form, which lives on near-shore reefs and washes ashore, is the typical form.

Figs 45, 46, 49
Etymology: Named for Maurice and Danielle Jay of Réunion, in recognition of their contribution to our knowledge of the Mascarene malacofauna, and in gratitude for the hospitality they afforded the author. Description: Shell: Small, turbiniform (L/D=1.00-1.16); teleoconch of up to 3.5 whorls; sculpture strongly cancellate; first whorl initially sculptured only by axial pliculae, relatively widely spaced at first, but becoming more close-set toward end of first half whorl; 3 spi ral cords develop during first whorl, one at mid-whorl, one between this and adapical suture and the third level with abapical suture; that at mid-whorl strongest and becoming pe ripheral cord of later whorls; cords become progressively stronger with growth, a fourth appearing below adapical suture during third whorl; axial pliculae more widely and regularly spaced from second whorl onward; pliculae cross cords producing angular nodules at intersections; in final quarter of last adult whorl an additional intermediary spiral cord arises between each of the primary cords (Fig. 45F); for the most part, inter vals between cords noticeably wider than cords themselves; last adult whorl with 25-30 pliculae; pliculae narrower than cords; interstices obliquely quadrate. Base with 4 somewhat more close-set spiral cords, including that level with suture, a weaker fifth one sometimes evident, closely juxtaposed to the fourth and spiralling into umbilicus; um bilicus remaining patent at maturity, its width variable between individuals, often some what obscured by reflected upper part of columella lip. Peristome markedly ob lique, almost tangential; aperture subcircular; columella concave, lacking dentition; outer lip notched at ends of spiral cords, somewhat thickened internally, but lacking both internal teeth and in-running ridges; interior of aperture nacreous, angled beneath external cords. Microsculpture (Fig. 46B, C): Vermiform spiral threads not evident on apical whorls; microsculpture between axial pliculae crisply granular; this persisting over much of adult shell, but traces of scratch-like sculpture evident in interstices; in fresh specimens microsculpture generally obscured by relatively thick intritacalx layer and additional superficial encrustations. Protoconch (Fig. 46A, C): White, not exsert, slightly down-tilted and more or less level with first teleoconch whorl; diameter 260-290 μm; terminal lip straight but with evidence of a small beak-like projection near adapical suture; superficial sculpture well developed, relatively coarse and widely spaced, arranged in irregular axial lines, with no spiral component evident. Colour: Shell more or less uniformly white to pale buff; with a dirty white, chalky intritacalx deposit.
Dimensions: Largest specimen, length 2.9 mm, diameter 2.5 mm. Operculum: Like that of V. natalensis. Radula and external anatomy: Unknown. Distribution and habitat (Fig. 49): Endemic to the tropical south-western Indian Ocean, ranging from the Mascarene Islands, particularly Réunion, to southern Madagascar and central Mozambique. No accurate habitat data available, but probably an inhabitant of near-shore, carbonate substrata and perhaps lagoons. Remarks: This material is confusingly similar to specimens of V. natalensis from off-shore habitats, in which the axial pliculae cross the spiral cords to produce a more angularly nodular sculpture. The principle discriminant character of the present material is the appearance of intermediary spiral cords above the periphery of the final quarter of the last adult whorl. Such intermediary cords are never evident in V. natalensis. In addition, the axial pliculae on the first teleoconch whorl are considerably more close-set in V. jayorum and the intritacalx deposit is more uniformly pale in colour, lacking the greyish axial banding common in V. natalensis. There is also some resemblance to V. favosus (Melvill & Standen, 1896), a poorly known species from the Loyalty Islands. However, the figured syntype of that species (MMUM EE.3734; here re-illustrated and designated lectotype, Fig. 70E-G) also lacks intermediary spiral cords in the final quarter of the last adult whorl, and it has a wider umbilicus than any of the south-western Indian Ocean species of Vaceuchelus.

Description:
Shell: Small, turbiniform; spire height rather variable (L/D=0.90-1.2); teleoconch of up to 3.5 whorls; sculpture strongly cancellate; first whorl initially sculptured only by relatively widely spaced axial pliculae (16-18), but 3 spiral cords develop soon thereafter, one forming shoulder, another level with abapical suture and the third between these, at whorl periphery; cords persist and become progressively stronger with growth; a fourth cord may develop on shoulder during last or penultimate whorl, but otherwise there are no intermediaries; intervals between cords noticeably wider than cords themselves; cords sometimes weakly and rather irregularly granular where crossed by axial pliculae (see notes below); last adult whorl with 22-30 pliculae; pliculae narrower than cords; interstices obliquely quadrate. Base with 4 somewhat more close-set spiral cords, including that level with suture, with a weaker fifth one spiralling into umbilicus; umbilicus narrowly patent, partly obscured by reflected columella lip. Peristome oblique; aperture subcircular; columella concave, lacking dentition; outer lip strongly notched at ends of spiral cords, even in the largest specimens; interior of aperture nacreous, lacking internal teeth or spiral ridges, but angled beneath external cords. Microsculpture (Fig. 48B, C): Vermiform spiral threads not evident on apical whorls, but traces of microscopic granular sculpture present; scratch-like microsculpture weakly evident in sculptural interstices of adult shell, but microsculpture generally obscured by granular intritacalx deposit. Protoconch (Fig. 48A, C): White, a little exsert and slightly down-tilted; diameter 280-300 μm; lacking an apical beak; terminal lip more or less straight to weakly convex, and slightly flaring; superficial sculpture well developed, arranged in irregular axial lines, with no spiral element evident. Colour: Shell whitish, living specimens with a dirty buff intritacalx deposit, usually with darker, ashy-grey axial bands, some iridescence in cord intervals; dead shells usually with only traces of intritacalx remaining, mostly in interstices.
Operculum (Fig. 4K): Relatively tightly multispiral throughout. Radula (Fig. 48D, E): Formula ∞+2+1+2+∞; ca 60 transverse rows of teeth; transition from lateral to marginal series relatively clear. Rachidian with large trigonal cusp and well-developed hood; cusp with very strong transverse ridge at its base; cutting edge coarsely dentate, central denticle largest, lanceolate, with approx. 4 smaller denticles on each side. Only 2 lateral teeth evident, their cusps spathulate with coarsely and deeply dentate margins. Marginals resembling those of Herpetopoma, the inner ones with cusp coarsely pectinate on outer margin; remaining marginals with smaller more finely pectinate cusps, but those at radula margin broader and flatter. External anatomy (Fig. 6G): Head-foot translucent milky-white when alive, snout and neck with some greyish pigmentation. Cephalic lappets present but small and not extending across forehead; right postocular peduncle well developed, similar in size to eyestalk or perhaps larger; right subocular tentacle not evident; neck lobes similar, each with 5 or 6 tentacles of varying size; epipodium posterior to neck lobes with 4 or 5 tentacles of varying sizes on each side, with an epipodial sense organ faintly dis cernable at base of larger ones.
Vaceuchelus semilugubris (Deshayes, 1863) Figs 4L, 50, 51  Poppe et al. 2006: 47. Description: Shell: Small, turbiniform, robust; length more or less equal to diameter (L/D=0.92-1.04); teleoconch of approx. 3.5 whorls, but apex usually badly eroded; sculpture cancellate; first whorl strongly shouldered at mid-whorl, almost horizontal above shoulder and vertical below it; shoulder develops into a strong spiral cord at end of whorl, another cord evident at level of abapical suture; axial pliculae do not develop until near end of whorl; this sculpture strengthening during second whorl with an additional cord arising between first cord and adapical suture; these two cords becoming the large peripheral and supra-peripheral cords of last adult whorl; 1-2 additional secondary cords arising above supra-peripheral cord during third whorl; axial pliculae stronger on second and subsequent whorls, prosocline and raised into granules where they cross spiral cords, granules somewhat angular on second whorl, but becoming progressively more rounded and bead-like on subsequent whorls; interstices quadrate; last adult whorl with 25-30 pliculae. Base with 5 spiral cords, the first level with suture, the fifth small and spiralling into umbilicus; umbilicus narrowly patent even in adults. Peristome oblique and nearly tangential, aperture subcircular; columella shallowly concave with a rounded tooth at its base; interior of outer lip of mature individuals subterminally thickened and set with approx. 10 ridge-like denticles, with an additional row of smaller granules just inside lip edge; apertural dentition absent in immature specimens, in these the outer lip is strongly notched at ends of spiral cords; interior nacreous, weakly angled beneath external cords, but labral denticles not extending into aperture as in-running ridges. Microsculpture (Fig. 51A, B): Juvenile microsculpture comprising irregular vermiform spiral threads; subsequent microsculpture mostly granular, but with traces of scratchlike markings.
Protoconch (Fig. 51C): White, slightly exsert, eroded in most material; diameter ca 285 μm; strongly sculptured with an irregular superficial reticulation showing traces of axial alignment, but no spiral element. Terminal lip more or less straight, but perhaps evincing signs of a broken beak-like projection; becoming concave toward abapical suture. Colour: Shell white, variously patterned with black spots, blotches or axial bands, ori entation of pattern prosocline in some specimens, opisthocline in others; markings ge nerally finer on base; pattern fading to brown in old material. Occasional specimens with almost no black markings (Fig. 50F). Coloration of fresh specimens somewhat obscured by dirty buff intritacalx deposit, superficial calcareous encrustations and debris.
Operculum (Fig. 4L): Relatively tightly multispiral throughout. Radula (Fig. 51D, E): Formula ∞+3+1+3+∞; ca 50 transverse rows of teeth; transition from lateral to marginal series clear. Rachidian with broad, trigonal cusp, well-developed hood, and a distinct transverse basal ridge; cutting edge with a slender, acuminate central denticle and 2 or 3 progressively smaller, similarly shaped denticles on each side. Lateral teeth all of similar size, their cusps with coarse lateral denticles on both margins (3-5), those on the third lateral particularly strong. Marginals closely resembling those of Her petopoma scabriusculum, the cusps of the inner ones with a strongly pectinate outer margin; outermost marginals shorter and with a slightly dilated, fringed cusp.
External anatomy: Only dried material available; evidently chilodontid but insufficient detail evident. Type material: Two syntypes of Turbo semilugubris Deshayes, 1863, in MNHN, the one in better condition is here figured and designated lectotype (MNHN 24658) (Fig. 50A, B), length 3.10 mm, diameter, 3.05 mm.
Distribution and habitat: Known only from the island of Réunion; Jay (2009) recorded it as living under stones at -10-15 m, but noted it to be rare. Remarks: There appear to have been no published records of this species since its original description. Subsequent mentions of the name are either simple listings (Martens 1880;Viader 1937) or mere translation of the original description (Pilsbry 1888), and there is no evidence of new material having been examined. However, additional samples clearly referable to this species have been found on Réunion, confirming that the original provenance was correct. The occurrence of the species in Mauritius requires confirmation. Pilsbry (1888) and Viader (1937) mentioned this island, but it is not clear whether this was a generalisation or specifically intended to mean Mauritius rather than Réunion. Despite extensive searching for micro-molluscs in beach-drift samples and hand-dredged sand from near-shore reefs on Mauritius (by Kilburn and Herbert), no specimens of V. semilugubris have been collected. Nonetheless, it is clearly not common, even on Réunion. Given the proximity of Réunion and Mauritius, it would be surprising if the species did not occur on both islands. Whether this species should be referred to Vaceuchelus or Herpetopoma requires further study. I have chosen to refer it to Vaceuchelus on account of the shape of the shell and its relatively coarse, cancellate sculpture. The presence of denticles inside the outer lip is a feature common to both Vaceuchelus and Herpetopoma. However, in the present species there is also a distinct denticle at the base of the columella that delineates a notch (albeit weak) at the junction of the basal and columella lips. This is a feature more typical of Herpetopoma.
The species is distinctive amongst small chilodontids of the south-western Indian Ocean on account of its bold, axial colour bands and relatively wide umbilicus. In fresh shells these bands are very dark purplish brown to almost black, but fade to a paler maroon-brown in old and sun-bleached specimens. They are clearly part of the shell, unlike the greyish axial bands seen in fresh material of other species (e.g. V. nata lensis), which are part of the superficial intritacalx deposit. Rarely, specimens are almost devoid of black markings and may easily be confused with the sympatric V. jayorum (above). That species, however, has strong close-set axial pliculae on the first teleoconch whorl, has intermediary spiral cords on the last quarter of the final whorl, and does not develop labral dentition when mature. I suspect V. semilugubris may exhibit ecological variation in shell morphology, ranging from typical boldly marked specimens with coarse sculpture, to somewhat smaller specimens with little or no colour pattern and finer sculpture (Fig.  50F). However, since accurate information on habitat is not available, this remains a spe culative observation. Shells of Perrinia species are small (length <20 mm) with relatively flat-sided whorls, resulting in a trochiform spire. The suture is frequently strongly indented and the peri-phery often angular and/or keeled. The apical whorls are sculptured only with axial pliculae and subsequent whorls with both spiral cords and axial pliculae that interact to produce a cancellate or foveolate sculpture (not obviously beaded). The columella has a single, relatively weak tooth or knob near its base, there is no inductural callus shield, the umbilicus is generally closed, and the interior of the outer lip bears spiral ridges that extend deep into the aperture. The juvenile microsculpture is granular and lacks vermiform spiral threads, and the adult microsculpture of close-set, scratch-like, axial marks is well developed.
Perrinia has long been regarded as a subgenus of Turcica H. & A. Adams, 1854 (type species Turcica monilifera A. Adams, 1854, by monotypy), but I consider Perrinia species to form a relatively well defined group which can be reasonably easily separated from the much larger Turcica s.s. species on account of their smaller size, stouter shells and strong spiral lirae inside the outer lip of the aperture. In the absence of data suggesting otherwise, I therefore accord Perrinia full generic status.

Description:
Shell: Elevated trochiform (L/D=1.24-1.5); apical angle 50-60°; teleoconch of up to 7.5 whorls (apical ones frequently badly eroded or missing); apex truncated; spire whorls somewhat flat-sided, but still retaining a degree of curvature; periphery angular, but not keeled; suture inserted below peripheral angle, level with subperipheral cord creating a narrow channel. First teleoconch whorl sculptured initially only with axial pliculae (±30); 3-4 spiral cords develop during second whorl; cords crossed by crispate axial pliculae; third and subsequent whorls with 5-6 broad, rather uneven spiral cords above and including peripheral one; subsutural cord rendered coronate by well-developed triangular nodules arising from approximately alternate axial pliculae; nodules frequently apically bifid on later whorls; interaction of spiral and axial elements producing a foveolate sculpture with rectangular to D-shaped pits; shell also sculptured by broad, opis thocline (rarely orthocline) ribs, stronger in some specimens than others, 11-15 on last adult whorl; ribs for the most part arising from subsutural coronations (not inva riably), strongest at periphery and rendering shell circumference undulant or even weakly stellate (infrequent). Base sculptured by 6-8 spiral cords; cords near umbilicus weaker than those toward periphery; axial pliculae evident in cord intervals, especially that between peripheral and subperipheral cords, weakest and almost obsolete near um bilicus; pliculae interact with cords causing some weak granulation of the latter; um bilicus closed in adults, but patent in very young individuals. Peristome oblique; aperture D-shaped, flattened at parietal and columella lips; columella (at maturity) with a relatively prominent tooth approximately one third of length from basal lip, occasionally also with a very low swelling apical to this; interior of outer lip with up to 16 spiral lirae running into aperture (only in mature shells), those nearest shell axis may terminate on base of columella and appear as small denticles below columella tooth; outer lip prosocline, its margin thin, but becoming thicker internally. Microsculpture (Fig. 53B, C): Juvenile shell with finely granular microsculpture, vermiform spiral threads not evident; adult shell with well-developed scratch-like microsculpture, which is filled with intritacalx deposit in fresh shells.
Protoconch (Fig. 53A, C): Translucent white; diameter ca 260 μm; not projecting above first teleoconch whorl, shell apex thus appearing truncated and somewhat tilted; missing or badly eroded in most specimens; surface sculptured with a fine, irregular granulation; terminal lip strongly angled above mid-whorl.
Colour: Ground colour generally greyish white to pale buff; basal spiral cords commonly marked with brown flecks; some specimens with a reddish or brown spiral band below suture and another at periphery; entire surface covered with off-white, chalky intritacalx deposit. One specimen almost entirely brownish grey, with a dark, ash-grey intritacalx. Most shells encrusted to some degree with other organisms, frequently coralline algae and bryozoans.
Radula (Fig. 53D-F): Formula ∞+3+1+3+∞, with ca 60 transverse rows of teeth; lateral flanges of rachidian well developed creating a distinct hood, cusp with a strong transverse basal ridge, the apex broadly trigonal with stout denticles, a larger, lanceolate median one and 2 or 3 smaller ones on each side. Laterals overlapping extensively, their cusps trigonal and noticeably asymmetrical; central denticle largest, lateral denticles well developed on outer margin, progressively decreasing in size toward tooth shaft; inner margin with fewer denticles. Marginals numerous and slender, cusps of inner ones recurved and coarsely pectinate, outer ones spathulate distally with a feathered edge.
External anatomy (Figs 5B, 6E): Body white with pale brownish maculations on sides of foot and underside of epipodium, snout heavily marked (transversely) with dark brown to black. Snout expanded laterally, but not strongly so; free margin of cephalic lappets relatively coarsely divided (2-3 digits); right post-ocular peduncle well developed, arising beside base of eyestalk, somewhat flattened and with a distinct dorsal groove; right subocular tentacle not evident; left neck lobe with numerous tentacles of varying size, right lobe with finely fimbriate margin and approx. 3 tentacles in anterior half; 6 or 7 large epipodial tentacles on each side, with frequent smaller intermediary tentacles of varying size; an indistinct epipodial sense organ present at base of larger epipodial tentacles, none evident under neck lobes.
Type material: Three syntypes of M. angulifera A. Adams, 1853, in NHMUK (1968215), the largest is here figured and designated lectotype (Fig. 52A), length 12.9 mm, diameter 8.9 mm. Holotype of C. pliciferus Schepman, 1908 (Fig. 52C), in ZMAN (3.08.028). Holotype of T. montrouzieri Fischer, 1878 (Fig. 52B), in MHNB (Herbert 1996) and there is an 'ex auctore' specimen in MNHN, but this has no type status.  Distribution and habitat (Fig. 54): Indo-West Pacific; from SE Asia and northern Australia, to the Andaman Islands, Maldive archipelago (Smith 1903), Mascarene Is lands and the continental margin of the western Indian Ocean, from Muscat (Melvill 1928) south to northern South Africa. Off Zululand, this species was dredged, in relative abundance, amongst old coral rubble and pebbles encrusted with Lithothamnion growths lying on a substratum of coarse bioclastic sand, at depths of -50-80 m (living specimens -50-65 m). Cantharidus pliciferus was also found on a substratum described as a 'Lithothamnion bottom' (Schepman 1908). In fully tropical areas the bathymetric range evidently extends into shallower water (to -10 m). Deep-water material from Réunion (-170-225 m) comprised only long-dead specimens that probably originated in shallower habitats on the island's steeply shelving coast. Remarks: South-western Indian Ocean examples of this species generally have fewer (11-15), broader axial ribs than is typical (18 on last adult whorl in NHMUK types) and the axial pliculae between the spirals cords are less close-set. However, in other respects they are indistinguishable and I have little hesitation in referring them to Adams' species. Such small differences are not unexpected in material from such widely separated localities. Cantharidus pliciferus Schepman, 1908 from the Sulu Archipelago is simply a subadult specimen of the present species and Tectaria montrouzieri Fischer, 1878 from New Caledonia, is a very typical adult (Herbert 1996), albeit rather small. The broad, opisthocline ribs of this species set it apart from all others of the genus, even those of similar size, e.g. P. chinensis (Sowerby, 1888) from Hong Kong (Fig.  71A, B), P. maculata (Brazier, 1877) from northern Australia (Fig. 71C, D) and P. elisa (Gould, 1849) from Singapore. Amongst local species, P. konos is very much smaller and P. stellata has a carinate and strongly stellate periphery.

Description:
Shell: Small, elevated-trochiform to turriculate (L/D=1.26-1.50); apical angle 55-60°; teleoconch of 6-7 whorls; whorls flat-sided and peripherally angled, peripheral angle marked by a strong keel, base flattened; sutures channelled and inserted below peripheral angulation, spire thus rendered pagodaform; insertion of suture level with subperipheral spiral cord. First teleoconch whorl more or less evenly rounded and sculptured only with strong, evenly spaced, axial pliculae (14-20); peripheral cord (angulation) begins to develop during second whorl, axial pliculae become nodular at angulation; whorls more flat-sided from third whorl onward and with 2 or 3 further spiral cords, one immediately below suture and 1 or 2 between this and peripheral keel; subsutural cord with adapically pointed triangular nodules which project into sutural channel; nodules with a thin lamel late ridge running into suture; middle spiral cord(s) thinner than the other two and at most obsoletely granular where crossed by axial sculpture; peripheral cord becomes keel-like with growth and is rendered stellate in apical view by radiating triangular nodules, 13-20 on body; axial sculpture of prosocline pliculae persists throughout, but pliculae more numerous than either the subsutural or peripheral nodules; whorl surface rendered somewhat cancellate/foveolate by interaction of spiral and axial sculpture. Base with 4 (rarely 5) evenly spaced spiral cords, outer one weakly undulant, others pro gressively smoother toward columella; interval between peripheral and subperipheral cords deeply concave and forms suture channel in spire whorls; innermost basal spiral very close to columella; umbilicus patent in juveniles, but closed by thickened columella in adults. Aperture subcircular, somewhat flattened in parietal and columellar regions; co lumella (at maturity) with a bulge-like swelling at its base, rarely forming a distinct tooth; interior of outer lip with up to 11 spiral lirae running into aperture (evident only in fully mature shells), one where basal portion of lip joins columella not enlarged; outer lip prosocline, not obviously thickened; interior nacreous. Microsculpture (Fig. 56B, C): Initial whorls lacking vermiform spiral microsculpture; later whorls with distinct scratch-like microsculpture. Protoconch (Fig. 56A, C): White to translucent white, strongly exsert; diameter 260-280 μm; apical beak scarcely evident; surface evidently smooth; terminal lip round ly angled between mid-whorl and adapical suture.
Colour: Ground colour yellowish white to pale orange, commonly buff; frequently with spots and blotches of a deeper shade beneath suture and at periphery; basal cords often spotted with dark brown; occasional specimens almost entirely pink with deeper pink markings; intritacalx deposit generally cream-yellow, only visible in the freshest specimens; shell frequently encrusted with bryozoans, sponges, tubicolous worms and encrusting Foraminifera.
Radula: Formula ∞+3+1+3+∞, with ca 70 transverse rows of teeth; similar to that of P. angulifera in that the cusp of rachidian is strongly dentate, with a sharply pointed central denticle and several similar but smaller lateral denticles on each side; laterals with a sharply pointed central cusp; marginals very numerous and fine.
External anatomy: Little preserved material available, but evidently similar to that of P. angulifera.
Type material (four syntypes of Turcica konos Barnard, 1964, in  Distribution and habitat (Fig. 57): South-western Indian Ocean; from northern Mada gascar to Mozambique, extending south to the Great Kei River, Eastern Cape, South Af rica; -47-250 m, living specimens -55-110 m, on varied substrata, but usually associated with sponge and coral rubble.
Remarks: Distinctive amongst local species on account of its small size and turriculate profile. Specimens from Madagascar often rather broad and with a more coarsely stellate peripheral cord. Perrinia angulifera (A. Adams, 1853) has a similar elevated-trochiform spire, but is less pagodaform and much larger (length up to 16 mm). The most similar sympatric species is P. stellata (A. Adams, 1864), but that also generally attains a larger size (length up to 9.6 mm in south-eastern Africa) and has a much more strongly stellate periphery and stronger basal cords. Schepman (1908) described a number of new species of this genus (placed as a subgenus of Calliostoma) from Indonesia, two of which, P. squamocarinata and P. nigromaculata, resemble the present taxon. P. squamocarinata (syntype examined, ZMAN 3.08.084, Fig. 71E, F) (additional figures provided by Poppe et al. (2006) and Poppe & Tagaro (2008)) differs in having stronger granules on the spiral cords above the peripheral keel on the last adult whorl, and the base retains an umbilicus (albeit small) and has five granular spiral cords (usually only four in P. konos) with strong axial pliculae in their intervals. P. nigromaculata (holotype examined, ZMAN 3.08.087, figured by Poppe et al. 2006) is less strongly keeled than P. konos and is larger (length ca 10 mm), has finer, more numerous spiral cords and a much more prominent tooth at the base of the columella (additional figures provided by Tsuchida & Ikebe (1990), Tsuchida & Kurozumi (1992), Poppe et al. (2006) and Poppe & Tagaro (2008)). Also from the Phi lippines, the recently described Perrinia cecileae Poppe, Tagaro & Dekker, 2006 has a similar elevated conical profile and is of a similar size, but it has more numerous spi ral cords above the periphery, a weaker peripheral keel on the spire whorls, and much stronger columella teeth. Turcica (Perrinia) morrisoni Ladd, 1966  Perrinia stellata: Kendall & Skipwith 1969: 855;Bosch et al. 1995: 33, fig. 28;Hoenselaar & Dekker 1998: 199;Rusmore-Villaume 2008: 20;Zuschin et al. 2009: 99, pl. 9, figs 5-7; Bandel 2010: 470, fig. 15d-f.

Description:
Shell: Elevated-trochiform to turriculate (L/D=1.10-1.65); apical angle 42-63°; teleoconch of up to 8 whorls; whorls flat-sided and periphery angular, marked by strong, stellate, keel-like spiral cord, below which is a distinct supra-sutural sulcus. First teleo conch whorl rounded and sculptured only with close-set, curved, axial pli culae (±35); weak spiral cords develop toward end of second whorl; supra-sutural cord rapidly strengthening during third and subsequent whorls, and developing cha racteristic squamose, stellate projections; projections becoming fewer and larger with growth (±15 on last adult whorl); uppermost cord also strengthens, but to a lesser extent and becomes coronated by apically orientated, scale-like granules; these 1.5-2 times as numerous as peripheral projections; in terval between peripheral cord/keel and abapical suture progressively deeper and more channelled with growth; development of remaining spirals between adapical suture and periphery variable, sometimes distinct, sometimes obsolete; axial sculpture becoming less obvious with growth; apical whorls (not first) somewhat cancellate, becoming more foveolate with elongate D-shaped pits on later whorls; pliculae in supra-sutural sul cus usually stronger and less close-set than those above peripheral keel. Base with 4 welldefined spiral cords and a fifth adjacent to columella; outermost cord strongest and fre quently set with scale-like granules, in large specimens the other basal cords may also be somewhat granular; umbilicus closed. Peristome oblique; aperture D-shaped; columella more or less straight, a single weak tooth or rounded bulge present at its base in mature specimens; outer lip strongly notched at ends of peripheral and basal cords, particularly in subadults; interior of outer lip weakly thickened with in-running ridges at maturity, but most local material somewhat subadult in this respect; interior of aperture nacreous, angled beneath peripheral cord. Microsculpture (Fig. 59B, C): Initial whorls somewhat worn in all available material, but evidently lacking vermiform spiral microsculpture; later whorls with distinct scratchlike microsculpture.
Protoconch (Fig. 59A, C): Apex missing or heavily encrusted in most specimens; protoconch remaining only in some juveniles and rather worn even in these; translucent white; diameter ca 260 μm; moderately exsert; terminal lip roundly angled between mid-whorl and apical suture; superficial sculpture eroded in all available material.
Colour: Shell milky-white, fresh specimens with a cream to dirty buff intritacalx deposit, often with broad, dark greyish axial bands, particularly in juveniles. Many speci mens with heavy, whitish or pinkish coralline encrustation.
Dimensions: Largest specimen (holotype of Tectaria armata), length 15.5 mm. Southeast African specimens develop mature apertural features at a smaller size than those from the north-western Indian Ocean and Red Sea, and never attain such a large size (largest southern African specimen, length 9.6 mm).
Operculum (Fig. 4O): Initially tightly multispiral, but whorls broadening with growth and becoming more openly multispiral, although somewhat less so than in P. angulifera and P. konos.

Radula: Unknown.
External anatomy: Like that of P. angulifera; only small specimens available, but no clear differences are apparent.
Type material: Holotype of Turcica stellata A. Adams, 1864 (Fig. 58A), in NHMUK (1968214). Holotype of Tectaria armata Issel, 1869 (Fig. 58F), in MCSNG. Distribution and habitat (Fig. 60): Persian Gulf, Gulf of Oman, Arabian Sea, Red Sea, Suez Canal and East Africa south to the KwaZulu-Natal south coast (Scottburgh area); living material collected from -18-50 m in South Africa, but probably also occurring in shallower water in truly tropical areas; available data on habitat preferences is incon clu sive. A record from Zambales in the Philippines (Hidalgo 1904-05) requires con firmation. Remarks: A characteristic species though somewhat variable in size and shell proportions. The only local species with which it might be confused is P. konos, but that species is smaller, never has such strongly developed peripheral projections, has weaker basal cords and more widely spaced axial pliculae on the apical whorls. Turcica (Perrinia) mor risoni Ladd, 1966 from the Marshall Islands, is smaller, less elevated and has much more obvious dentition inside the outer lip. Tomlin (1927) followed by Lamy (1938) synonymised Tectaria armata Issel, 1869 from the Red Sea, with the present species. The figure of the holotype here provided (Fig.  58F) indicates that this was fully justified. Tomlin (1927) also questioned the validity of the original Cumingian locality data, China Seas. This is a notoriously vague locality which should be rejected in view of the known inaccuracy of the provenance attached to much Cuming material. With the exception of one unconfirmed record from the Philippines (Hidalgo 1904-05), the species has been recorded subsequently only from the western Indian Ocean. I here emend the type locality to be the Gulf of Suez.
Etymology: From Greek pholidotos (scaly) and trope (a turn); in reference to the scalelike sculpture on the spiral cords. Gender feminine. Type species: Pholidotrope gloriosa sp. n. Diagnosis: Shell small, profile conical with narrowly indented suture; suture level with subperipheral cord; sculpture coarsely cancellate with scale-like projections on spiral cords; columella with a single basal tooth; interior of outer lip thickened and set with ridge-like denticles, that nearest columella largest and separated from basal columella tooth by a U-shaped notch; denticles do not extend into aperture as in-running ridges; umbilical and parietal region covered by glossy inductural callus shield; aperture obliquely tangential to base of last adult whorl; outer lip with low subterminal external varix; protoconch exsert.
Remarks: Pholidotrope resembles Clypeostoma in possessing a well developed basal callus shield, but differs in being smaller, having a more conical profile, coarser sculpture, only one tooth on the columella and a subterminal external varix behind the outer lip. It also resembles Mirachelus Woodring, 1928 from the western Atlantic and eastern Pacific, but species of that genus lack an expanded basal callus and a subterminal external labral varix. Perrinia likewise lacks both these features, and in addition its aperture is spirally corded within and the dentition at the base of the columella is weaker.
Figs 61, 62 Etymology: From Latin gloriosa (famous, glorious); in reference to Îles Glorieuses, near which the type material was collected. Description: Shell: Trochiform, small, spire conical, base somewhat flattened (L/D=1.18); teleoconch of 5.5 whorls; initial whorls rounded, becoming more flat-sided with growth; suture narrowly indented; sculpture of spiral cords and lamellate axial pliculae; first whorl sculptured only by relatively widely spaced axial pliculae (13), second whorl with 16 axial pliculae and 2 developing spiral cords; third whorl with 17 axial pliculae and a third spiral cord developing at shoulder; fourth and fifth whorls with 3 strong spiral cords and 18 and 19 axial pliculae respectively; cords and pliculae subequal in strength, their intersections produced into scale-like nodules, those on shoulder cord somewhat more rounded; suture level with subperipheral cord; cord intervals wider than cords themselves, that between peripheral and subperipheral cord deep. Base with 4 spiral cords, progressively weaker toward centre; umbilicus narrowly patent in juvenile, but umbilical and parietal regions covered by a thin, smooth inductural callus spreading from aperture at maturity. Peristome markedly oblique, more or less in one tangential plane; aperture D-shaped; columella more or less straight, but with a distinct, roundly trigonal tooth near its base; outer lip internally thickened, its edge flaring outward; inner thickening with 10 ridge-like denticles, that nearest columella largest, creating a U-shaped notch between it and columella tooth; interior of aperture nacreous, labral denticles not extending internally as in-running spiral ridges; exterior of outer lip subterminally thickened by a low collabral varix. Microsculpture (Fig. 62A, B): Early whorls with close-set, microscopic granules, vermiform spiral threads not evident; fine, prosocline, scratch-like marks on later whorls. Protoconch (Fig. 62C): White, globose and distinctly exsert, diameter ca 280 μm; sur face worn, but with evidence of a fine, flocculent microsculpture; terminal lip convex. Colour: White. Dimensions: Holotype, length 4.7 mm, diameter 3.9 mm.
Operculum, radula and external anatomy: Unknown. Distribution and habitat: Known only from off north-western Madagascar, -35-250 m, presumably on rocky substrata. Remarks: The small size and conical profile of Pholidotrope gloriosa renders it distinctive amongst south-western Indian Ocean chilodontids. The only similar species, Perrinia konos, is more elevated, less coarsely sculptured and has less well-developed dentition at the base of the columella.
Genus Granata Cotton, 1957 Granata:  Thiele (1924Thiele ( , 1929 and Wenz (1938), following Gray (1847) and Pilsbry (1890Pilsbry ( in 1890, believed it to be S. imbricata and, recognising the true affinities of that species, placed Stomatella near Euchelus and Danilia. In contrast, most recent authors (e.g. Keen 1960;Hickman & McLean 1990) have followed Cotton (1957) who observed that Anton had designated Stomatella auricula as the type species of Stomatella, in his 3 Although Lamarck (1816) is traditionally cited as the author of Stomatella, the genus has recently been credited to Bowdich (1822) (Bouchet & Rocroi 2005). This stems from the fact that Lamarck's plate of Stomatia and Stomatella in his Tableau Encyclopédique (Lamarck 1816: pl. 450) has no associated legend and thus no species are listed under these names and it is not evident which figures he considered to belong to the respective genera. The legend is taken to have been eventually published in 1827 (Evenhuis 2003). Prior to this, however, Lamarck clarified his concept of these genera in his Histoire naturelle des animaux sans vertèbres (Lamarck 1822; April), where he described a number of species, but this was predated by a publication in which Bowdich (1822; February) discussed Stomatella, citing and il lustrating a single species, Stomatella imbricata, thus suggesting that Bowdich was the first to validly pro pose the genus. However, in reallity a legend was published in 1816 for the Stomatia and Stomatella plate in the Verzeichniss der Conchylien (Anton 1838, but cited as 1839), and that this pre-dated Gray's (1847) more widely known designation of S. imbricata. Macpherson and Gabriel (1962) claimed that no such designation existed in the Verzeichniss der Conchylien and believed Granata to be an 'absolute [objective] synonym' of Stomatella. Iredale and McMichael (1962) listed S. imbricata as the 'logotype' (type species by subsequent de signation) of Stomatella, citing Dujardin in Dictionnaire Universel d' Histoire Naturelle (d'Orbigny 1839-1849) and giving a date of 'ante 1845'. The most recent analysis of the dates of publication for the various volumes and livraisons of d'Orbigny's Dictionnaire (Evenhuis 1990), however, gives the date for volume 12, liv raison 133, pages 1-64 (entries Stellion to Strombides in the dictionary, Stomatella on p. 47) as 9 September 1848. Examination of Anton's Verzeichniss shows that a type designation is in fact present, though somewhat concealed. In the introductory pages to this work, Anton stated "…den Gattungen (deren typusart mit Versalbuchstaben gedruckt ist)" ["…the genera (whose type species are printed in capital letters)"] (Anton 1838: vi) and entry 1222 under Stomatella is printed "LUTEA = St. auricula Lam. = Patella lutea L.". However, since Stomatella lutea was not one of the nominal species originally included by Lamarck (1916) in Stomatella, it is not eligible for subsequent designation as the type species (ICZN 1999: Art. 69.1). This not withstanding, since Anton clearly indicated that he considered Patella lutea to be a synonym of Stomatella auricula, which was one of the species originally included in Stomatella, this is to be considered a valid fixation of the latter species as the type species of the genus (ICZN 1999: Art. 69.2.2). Dated 1838 (Cernohorsky 1978a), it is evidently the earliest designation available. Like Anton, Lamarck himself considered Patella lutea and Stomatella auricula to be synonymous (Lamarck 1822: 210), though Pilsbry (1890 in 1890-91) believed P. lutea to be an unidentifiable entity. Remarks: Hickman (1998) believed Granata to be a monotypic genus endemic to the southern half of Australia. However, I follow other recent authors (e.g. Sasaki 2000;Poppe et al. 2006) in referring additional auriform chilodontids to this genus. While these may not be as depressed and haliotiform as the type species, they almost certainly belong to the same lineage. With these taxa included in Granata, it is evident that the genus is widely distributed in the Indo-West Pacific. In addition to being conchologically similar, G. sulcifera, like G. imbricata, has an enlarged right hypobranchial gland and secretes a noxious white mucus when irritated, and has a similar radula morphology.
The relationship of Granata and Stomatolina Iredale, 1937 (type species Stomatella rufescens Gray, 1847, by original designation) needs to be further investigated. Both stomatelline and chilodontid taxa have been referred to Stomatolina. Although the matter could be easily resolved by examination of the radula and external anatomy, the difficulty lies in obtaining reliably identified specimens of S. rufescens. On the evidence available Tableau Encyclopédique, in a 16-page "Liste des objets représentés dans les planches de cette livraison" that is unfortunately lacking in many sets of the work (Evenhuis & Petit 2003;Petit 2011). The author of Stomatella is thus indeed Lamarck (1816). This superficially trivial nomenclatural fact is of considerable significance, for had Bowdich (1822) been the first to validly propose the Stomatella, then its type species would (by monotypy) be Stomatella imbricata and not Stomatella auricula. This in turn would mean that the trochid subfamily currently known as the Stomatellinae ought no longer be known by that name, and the Stomatellinae/idea would in fact be an earlier name for the Chilodontidae. Fortunately such is not the case, but I document the matter to provide clarification. (Iredale 1937), it seems more probable that Stomatolina is stomatelline, perhaps close to Pseudostomatella Thiele, 1924. Though perhaps related to Granata, species of Hybochelus Pilsbry, 1890 (type species Stomatella cancellata Krauss, 1848, by original designation) differ in having a less expanded last adult whorl, an open umbilicus (typically) which is bordered by somewhat stronger cords, and an operculum which almost completely closes the aperture (pers. observ. Hybochelus mysticus (Pilsbry, 1890)). The genus occupies conchological morphospace somewhat intermediate between that of typical Euchelus and Granata. As indicated earlier (see Excluded taxa, p. 398), Krauss's Stomatella cancellata is an extralimital species and is not included in this revision.
Key to species of Granata in the south-western Indian Ocean 1 Aperture very broad, ratio of maximum:minimum aperture diameter 1.25-1.40; cream patterned with reddish to reddish brown spots that remain distinct on last adult whorl; axial sculpture of rather coarse, regular, crispate pliculae ....cumingii -Aperture not as broad, ratio of maximum:minimum aperture diameter 1.04-1.16; initially with purplish to greyish brown spots, becoming more densely pigmented on last adult whorl; axial sculpture of rather uneven growth-lines .  fig. 67. Type loc.: none originally given; here designated to be tropical East Africa. Stomatia cumingii: Chenu 1959Chenu in 1959Chenu -62: 364, fig. 2709 This species is similar to Granata sulcifera (below) and does not warrant a full re description. It differs most obviously in shape and colour, having a distinctly more elongate aperture (ratio of maximum:minimum aperture diameter 1.25-1.40 in G. cumingii compared with 1.04-1.16 in G. sulcifera) and a more consistent colour pattern of reddish or reddish brown spots on a cream ground that remain distinct even on the last adult whorl. In addition, the sculpture of G. cumingii is somewhat coarser, the axial pliculae more crispate and regular, and the interstices more obviously iridescent. Although smaller, the three specimens listed below, are almost identical with the holotype and are undoubtedly conspecific therewith. Besides mention in late nineteenth century iconographies (Sowerby 1874;Pilsbry 1890Pilsbry in 1890, this species seems not to have been discussed in the literature subsequent to its original description. No locality data accompanied the holotype and, until now, the provenance of the species has remained unknown. Granata lyrata (Pilsbry, 1890), from Japan, which is also reportedly more strongly sculptured than G. sulcifera (Sasaki 2000), as a less elongate aperture and has greyish rather than reddish maculations. Microsculpture: Similar to that of G. sulcifera. Protoconch: Missing in all available specimens. Operculum: Oligospiral; like that of G. sulcifera. Radula: Unknown. External anatomy: Only one, badly contracted specimen available, but evidently similar to that of G. sulcifera.

Description:
Shell: Depressed turbiniform to auriform (L/D=0.74-0.90), last adult whorl expanding rapidly; teleoconch of up to 4 whorls; suture indented but not channelled, level with peripheral cord on spire whorls but descending below this near aperture; first teleoconch whorl initially more or less smooth, 3-4 spiral cords develop toward end of whorl; second whorl with 4-5 cords and further cords arising by intercalation with growth on subsequent whorls; end of penultimate whorl with 4-6 first-order cords; intervals between cords wider than cords themselves and usually with a weaker intermediary lira (frequently more than one near end of last adult whorl); axial pliculae develop during second and third whorls; pliculae initially rather regular and producing somewhat cancellate sculpture (second whorl), becoming finer, more close-set and irregular with growth; last adult whorl also with strong, irregular growth-lines; upper cords granular, those nearer periphery smoother. Base similarly sculptured, but cords lower; umbilicus lacking; aperture large, ovate; maximum:minimum aperture diameter 1.04-1.16; columella nacreous and lacking denticles, strongly concave, its junction with basal lip scarcely delimited; interior of outer lip not obviously thickened and lacking denticles or ridges; interior of aperture highly nacreous when fresh, with weak anglulations underlying external cords. Microsculpture: Vermiform spiral threads not evident on juvenile shell, but surface of early whorls generally worn; later whorls with fine scratch-like axial microsculpture (Fig. 67A).
Protoconch (Fig. 67B): White, diameter 250-270 μm; usually missing, damaged or badly eroded; protrudes slightly above first teleoconch whorl; sculptured with a coarse ly flocculent sculpture with some traces of spiral threads (perhaps resembling that of Clypeostoma salpinx when fresh); apex weakly beaked; terminal lip with a welldeveloped projection just above mid-whorl, angular in some specimens rounded in others.
Colour: Initially whitish, with dark purplish or greyish brown spots appearing on cords during third whorl; subsequent whorls spotted, blotched or washed with similar shades, last whorl sometimes heavily so; in living specimens coloration frequently obscured by a dirty brownish periostracal layer. Dimensions: Largest specimen, maximum diameter 21.6 mm, height 19.2 mm. Operculum (Fig. 4C): Oligospiral; somewhat thicker than in other chilodontid genera; maximum diameter approx. half maximum diameter of aperture; frequently damaged. Radula (Fig. 67C, D): Formula ∞+(3-4)+1+(3-4)+∞, with 90-100 transverse rows of teeth; rachidian relatively weakly hooded, cusp acutely trigonal with margins serrated by lateral denticles. Lateral teeth overlapping extensively, their cusps similar to that of rachidian, but slightly asymmetrical and a little larger; whether the fourth tooth should be considered a lateral or a marginal is debateable (Barnard (1963) likewise observed a gradual transition from laterals to inner marginals). Remaining marginals numerous, longer and more slender, with recurved, pectinate cusps. In terms of its general form this radula is similar to that of the type species, G. imbricata, but in that species the tooth cusps are finer and more elongate (Hickman & McLean 1990;Hickman 1998). External anatomy (Fig. 6D): General body colour yellowish white, epipodium paler with a few scattered black blotches, also on sides of the foot; cephalic tentacles, forehead and snout usually with grey-brown to black pigmentation. Cephalic lappets, neck lobes and epipodial fold well developed, forming an almost continuous sensory skirt around aperture margin, as in other auriform vetigastropods (e.g. Haliotis spp.). Cephalic lappets moderately broad with close-set, stubby processes on free margin; snout laterally expanded; post-ocular peduncle present on right (in both sexes), arising from posterior base of right eyestalk; peduncle with a longitudinal dorsal groove evident in some specimens; a smaller subocular tentacle emerging from ventral base of right eyestalk (illustrated also in G. lyrata by Kano 2008: fig. 4). Neck lobes originate beneath eyestalks, overlapping snout flanges, and extend posteriorly for approximately half length of animal; free margin of both lobes microscopically fimbriate with micropapillate tentacles of 2 or 3 sizes emerging from beneath margin; more numerous on left lobe than right; neck lobes narrowing posteriorly and merge seamlessly with epipodial fold. Edge of epipodial fold set almost throughout with epipodial tentacles of varying size, their number depending upon animal size (approx. 10 major epipodial tentacles on each side in large specimens, with numerous smaller intermediaries). An epipodial sense organ is present at base of most of the larger epipodial tentacles, but usually small and indistinct; none evident below neck lobes.  (Dautzenberg 1929); Faux-Cap (25.567°S 45.517°E), Decary (Dautzenberg 1932); Cap Ste-Marie (25.599°S 45.137°E), Decary (Dautzenberg 1932, as Stomatella articulata).
Distribution and habitat (Fig. 65): Indo-West Pacific; from Japan (Sasaki 2000) and the Tuamotu Archipelago (Couturier 1907) in the east, to the eastern seaboard of Africa, extending south to the northern Eastern Cape (Coffee Bay, 32.00°S); common in the low intertidal and shallow subtidal down to -18 m (empty shells to -45 m), living specimens most often found under stones and dead coral blocks, sometimes in small groups, in both sheltered and somewhat exposed habitats; often where the rock rests on muddy sand and where conditions are somewhat anoxic (Kilburn 1972;Kilburn & Rippey 1982, and pers. observ.). Shells of living specimens frequently encrusted with tubes of spirorbid polychaetes, sometimes heavily so. Remarks: Granata sulcifera is the only chilodontid species commonly found living in tertidally in southern Africa and is easily recognised by its low spire and rapidly expan ding last adult whorl. Vaceuchelus gemmula and V. natalensis may also be found in tertidally in South Africa, but are less frequently encountered, and are probably often over looked on account of their small size.
Granata elegans (Gray, 1847) from north-eastern Australia, G. lyrata (Pilsbry, 1890) (not Stomatia lirata A. Adams, 1850 -a species of Pseudostomatella) from Japan, and G. maculata (Quoy & Gaimard, 1834), described from Vanikoro Is., need to be exa mined for comparison as potential synonyms, but G. sulcifera predates all. Much museum ma terial identified as G. elegans is in fact referable to G. sulcifera, and so probably are some literature references (e.g. ; unfortunately the whereabouts of the type material of Gray's species is unknown. G. lyrata reportedly differs from G. sul cifera in having a less rapidly expanding last adult whorl and in being more strongly sculptured (Sasaki 2000).
This species has also been recorded from Pleistocene shorelines in the southern and eastern Cape, South Africa (Schwarz 1910;Barnard 1962;Davies 1972). Although such a range extension would have been quite possible during warmer interglacial pe riods, these records require confirmation since there may well have been confusion with the somewhat similar Pseudostomatella orbiculata (A. Adams, 1850), which is not uncommon in raised beach deposits in the Algoa Bay-Mossel Bay area (Kilburn & Tankard 1975). The same may also apply to Sowerby's (1892) record of Stomatella articulata from the Bairstow collection (i.e. Port Elizabeth).